Re: Strength training questions
Don't worry about the time spent. 20 reps will take you 20-30 seconds. 5 heavy reps will take you 10 seconds. The overall time spent lifting/moving is very small, if you want to save time, cut down your rest time, but not to a degree of sacrificing strength for your working sets, remember its a strength day, not a conditioning day.
And with 20 pullups vs 5 weighted pullups, yes obviously the heavier one would be more beneficial for strength building. Pullups and dips are easier to add weight and keep the form solid, with pushups, bodyweight squats with weight in a backpack or something, things like that, the technique can go to pot at heavier weights for lower reps. I.e you can't do a 1 rep max on a pushup, it will be more a balance exercise I imagine.
Yeah I wouldn't worry too much about the one armed stuff, the time spent learning is not really worth it for your purposes, it was just an example of you getting stronger with higher reps and that it isn't a death sentence.
Plyometrics are as you said. Other exercises, maybe some medicine ball throws, straight throws or rotational throws. You don't go to failure with plyometrics. Emphasis is on EXPLOSION and maximal force exerted, stick to 6-10 sets of 2-5 reps.