a few general questions

Im taking a week off starting today because i joints are sore ( always popping , and as i continue to train , new things pop like my chest , and i do go heavy but not too heavy for me , and i use good form so , ill just blame my bad genes for my crappy body )and i want to be fresh for my new , hopefully plateau busting routine.  plus i have some shoulder injuries for a long while ig uess.... my left one ( including collar bone ) pops and crack with almost every set and sometimes every other rep in direct shoulder work outs and every rep on pull ups which prevents me from doing very many , no matter how controlled , and other stuff including back(and chest , ... i dont know why but my shoulder hurts even if i use good form. and seems to be the reason i cant bench more or lift heavier for back they even hurt when i do bicep curls?? i dunno why... maybe i clinch or tense up? but its frustrated me to some bad levels. i mean it shouldnt remotely hit my shoulders and i dont swing i use proper form .
 
anyway my shoulders are just wacked even traditional idiot proof stretches hurt and feel un effective.  same with exercises like lat raises  , i dont feel it in my shoulder no matter how light the weight and the form i use i feel it more in my traps.... god help me ! i have no shoulders!...and need some by summer... anyway the injuries are  in my left shoulder are where my bicep and shoulder meeet , ironically where i get alot of stretch marks and feel a stretch when i bench press , more then in my chest , god my genetics suck!. and in the rear delt area ,  i must have a pulled tendend or something.. plus god only knows why my collar bone pops , if anyone  knows how to correct it? but ya  i havent gone to the doc , cuz its sore but not doctor visit sore , unless its lasts longer then a week , anyway.... so since im taking the week off , im  still going to do abs , lower back , and legs , because these mucles groups despite my almost 2 years of lifting are areas i never worked out and have only been doing them about 2-3 weeks....
 
so is working those muslces while on a break a bad idea?
 
and should i be doing stretches for my shoulders? or should i just leave them alone to heal for the week?
 
and ofcourse my goal is mass gain , i still have a desire to gain 20-25lbs before i cut ,  im 183-185 full stomach and want to be  like 200 7-9% bf , right now its probably like 15%... so anyway i have reallly crappy endurence and iw ant to do cardio , i was thinking of doing a day or two this week , will cardio  inprove my endurence in weight training?.... and should i bother doing it now tho im still bulking , because i wass gunna start doing it 2-3 days a week HIIT training around spring time to be cut for summer ... my desire for it now is hoping it will give me a second wind when im lifting. will it?...... ps , i dunno why but i cant sleep on my shoulders its almost liek the injuries occurred from years of sleeping on my side.... because when i do now its like my body collapses and puts allt he weight on my shoulder