For using a belt, there are good arguments on both sides. And there is also the 'middle-ground' of not wearing one until you get above 85-90%, depending on what your top weight is.
I never wore one, but... I haven't trained in 6 weeks! Recovering from a very minor bulging disk in my back, which i have had for a looooong time, but worked around it. It has just suddenly become very evil on me (we think, see below).
Though, grain of salt, my chiro has made my back super-duper straight and happy, and i still have sciatica (pains associated with a bulging disk in lower back, etc, etc) which means it is probably NOT the bulging disk that did the pain (many people have bulging disks, but they do not effect you negatively) and maybe muscular, or my hips, etc..
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Mumma:
I personally would recommend the 1x5. and let go + stand up between EVERY rep, settle yourself, and go for the next. (rest-pause).
This will allow you to become more comfortable with heavier weights, and when you do reach very heavy weights, you'll probably end up training singles anyway! When i was healthy and training, i was pulling 5-8 singles, then dropping 20-25% of the weight and doing some more 'pump' sets (3-5 reps).
I have never done squats and deadlifts in the same session - so i do not know the effect on each other.
As for cleans, you could:
1. Alternate cleans and deadlifts (deadlifts are CNS draining, BUT at your level, this is not an issue). This is because they are both 'pulls'.
2. Clean before pressing. If once a set, you get 5-10 cleans a week. Or, clean before EVERY REP. which will give you 25-50 a week. I used to do high volume clean (every rep) and press and enjoyed it very much! You get a little rest between reps when you put the bar down (good thing, we are going for total reps, doesn't matter if you do 25 singles), and multiple stimulus of a pull and push on the muscles. Fun times. My shoulders blew up when i did this with high volume kettlebell clean+press (with KBs, i never touched the bell to the ground though, i swung it between my legs).
Fun times!