With squating if you don't have spotter's, rack, power rack, etc and run into trouble and want to get from under the bar than you might consider either of two options.. Most guy's will shrug the shoulders back and jump forward so the bar will roll off or even be pushed off by the shoulders/traps. Some will drop the head /shoulder down and jump back away from the bar and usually land on their butts. Of the two I would always jump forward if the opportunity is there.
When I made my best gain on the heavy breathing squats I most always had two very large Samoan gentleman yelling in my ear's that they would shoot my dog and burn down my house if I didn't make the last two or three rep's in the breathing squats for that workout. Fear is a great motivator..
That would be one set of the the squat and 1 set's only of Presses, dips, BB rows, Hi-pulls. . Really no need for extra direct arm work. That is based on a 3 times a week workout. If you do twice a week workouts than add an extra set to all of the above exercises except the squat, until your body gets use to doing them in the heavy, high rep style(probably 2 weeks ). Do straight arm pullovers after every set of breathing squats for 20 light stretch reps. Draw the legs up when doing the pullovers on a flat bench. This will allow for a better stretch, because when the legs are drawn up there is less resistence from the ab's.
I'll try to keep this simple thought it not always that way. This very heavy forced breathing style of squating (also can be used with the DL's, SLDL's, clean & jerks ..which are prime ball buster's, HI-Pulls, etc.) puts great demands on the metabolism which in return can influence chemical release, including test & GH's, to repair and adapt the body to the overwhelming stress put upon it. To meet these demands the body can become stronger and add muscle mass to ready it's self for the next workout. Remember to take three deep breathe before each rep and as many as you need between reps until you reach 20 or beyond. Every workout add a least 5lbs to the bar. Most guy's can't do this type of workout. Way too much blood, sweat and tears for them. But is can be worth the effort in the long run. Of course, in the long run, it's up to you.Good Luck.