1 five-rep max vs. 5 one-rep maxes

Your 'implication" is incorrect to begin with but that is actually irrelevant to your questions as stated in your topic title and the question within your second paragraph which is actually a different question.

1 set of 5 rep maxes is not equal to 5 sets of your 1 rep max because you would be using full muscle recruitment with the 1 rep maxes for 5 sets but only using full muscle recruitment for the latter reps, probably reps 4 and 5, on the 1 set of 5 rep maxes. Different weights.

The same is true for the question about 30 reps because you are using more muscle fibers as you near your 10 rep max but never reach that level of recruitment doing 1 rep of your 10 rep max X number of times. Same weights. Hence, different questions but same answer.

 

@OP: You need to read the FAQ's.
I'm of the opinion that a proper 5RM set for a trained lifter (ie. not a newb) is going to require full recruitment of all motor units involved from the first rep. It's heavy.
On the other hand, it's not going to be possible to complete 5 x 1RM in a reasonable time frame. The best you are likely to achieve is 5 heavy singles with a load that you can't get a double with.
The load is likely to drop a bit for each single, at least for the first few reps.
However, the point is that 5 singles with a load > 5RM load is going to place more strain on the working muscles and so it will elicit a PS response (ie. act as an effective load for hypertrophy) for more sessions than a 5RM load. The problem is that your form will probably be less than great and you're more likely to sustain an injury with such a heavy load. Even then, if your conditioning to the exercise is high, you may require more TUT than 5 heavy singles will supply in order to elicit as strong a PS response as 3 sets of 5 with close to a 5RM load.

 

No. The reverse is more true. In addition, I work out 5 times per week at low weight, 4 times at medium weight and 3 times when using near max weights.

 

You won't over train if you are not getting fatigued, having trouble sleeping at night, grouchy, etc. Just make sure to keep your calories high enough to absorb the higher volume. But, bear in mind that there is a point of rapidly diminishing returns after which you are merely burning calories and not adding much muscle. Everyone is different and there is no set rule although, in general, the more advanced you are, the higher the point of diminishing returns. Measure your ideal level of lifting by results, not soreness.

 

If you are never sore at all then you aren't doing enough.
One man's overtraining is not another's. If you are, in your words, "small and not very strong", you are going to be stressing your joints and tendons a lot less than a big, strong guy over the course of a typical cycle. You can probably keep the 5's going longer than most before you need to take a break.
Keep the 5s going until your progress stalls. Increment the loads each week. Eg. If you're training three days a week, try for a 5% increase on the final session of each week, preferable before a weekend break for a little extra recovery. If 5% is too much, make it 5lbs. Just keep incrementing until you stop progressing. Then SD before getting back to 15s.

 

The only time I get even a little bit sore at all now is after the first day of a minimum two week SD. I remember in middle school that we had to do a fitness test that involved max pull ups, max push ups and 100 sit ups. We were all crippled the next two days and walking all hunched over because our abs were so sore.

 

Crossfit is a great way to spend any and all of your freetime accomplishing something you could accomplish with only a few hours a week of training, all while risking injuries such as snapping your spine in half, muscle tears, etc. and also while trying to avoid destroying your kidneys by lifting yourself into a case of full blown rhabdomyolysis - or uncle rhabdo, as the crossfitters have taken to calling it.
Sure, it has it's good points but there is no reason to spend that much time in the gym when you can accomplish a hell of a lot more with your physique and general fitness while investing far less time and money into it. Don't fool yourself, crossfit gyms are a racket designed only to make their owners a ton of money. Many of them charge $100 USD or more for a monthly membership when you can find perfectly adequate, non-crossfit gyms that will give you a membership for a fraction of that cost. But it's a great thing to get into if you need validation from others in order to feel like you've done a real workout.

 

A "real workout" is a workout that accomplishes your goal. Many crossfitters will say things like "that isn't a real workout" if you aren't going balls to the walls with the same crazed intensity that they do in crossfit. This simply is not true. There aren't really any such things as fake workouts, it doesn't matter what routine or method you are using.

If you are trying to achieve muscle growth, this can be done with far less time investment than you are required to put in with crossfit. If you are trying to become stronger, you can do this with less time than crossfit requires. If you are trying to improve your cardiovascular ability, this can be done with far less time than crossfit asks of you.

 

The best thing about CF, IMHO, is that it has encouraged many more folks to have a go at OWL. Tons of lifters have had a go at PL at regular gyms because they have all the gear for it (a squat rack, a bench with stands and a space to deadlift) but far fewer gyms made it possible to have a go at snatch and C&J. CF gyms have changed all that. They always have a good selection of bars and bumpers and often have proper lifting platforms.
I had to pay a fiver the last time I visited a CF gym. Pretty standard rate for a non-member. I was there for a couple of hours and I could do exactly what I wanted. Plus a coach watched my snatches and gave me some tips. Not going to complain about that.
CF has probably done more to save US weightlifting than anything else. Many of the top US lifters (and some of the greats, such as Klokov and Ilyin) are making money putting on, or taking part in, seminars at CF gyms around the country.
I also like that CF has managed to appeal to the more physically-minded women out there: it's got them off machines and into more dynamic lifting. Some of them are now lifting weights that would put many guys to shame (including me). I wish more women would take up some form of training. CF gets a thumbs up from me for helping a bit.

 

Going to failure on some light, metabolic work isn't going to interfere with your HST results that much if you are already conditioned to this sort of training, provided you get enough extra calories to cover what you are burning up with the extra met work.
Going to failure with a light load is not going to burn your CNS out in the same way a heavy set to failure will. However, it will have some effect on your recovery, so you may want to stop shy of failure for met work during the heavier end of your cycle. Suck it and see.