all steroids increase collagen synthesis, test increases collagen synthesis up until dosages of around 250mg/wk then afterwards it starts to have a negative impact. it won't effect tendon strength or the tendons ability to keep up with your gradual strength gains. tears are caused more so by bad form, being "not warmed up", compounded microtrauma muscles sustain from inadequate recuperation that leads to too much strain on tendons. the decreased collagen synthesis will impair rate of recovery time from injuries like tears and such, but it's not significant.
liquids and tabs are the same thing. with liquids you can inject them, but risk infection and abscesses if you don't filter them first because they won't be sterile, plus they contain a lot of solvents that are going to hurt when injected.
'var is a good roid, but it's not going to do much for alleviating joint pains and might even increase it depending on how you respond to var. nandrolone is the best and most effective for this, others might indirectly help lubricate joints by increasing water retention which can also exasperate the problem if there's too much fluid retention. if you use too much adex, you'll have the opposite effect and dry your joints out, having subsequent increased joint pains. the problem with var is that it's hard to get good quality var so keep that in mind, as people often get underdosed and unconsistent quality var, occasionally the var gets conterfeited by something else (winny usually)
i don't like test and i generally recommend other roids over test, but it depends on your goals and aspirations. it gets the job done.
hcg: yes on cycle
don't run nolva throughout the cycle, get some letro in case of a gyno flareup. it's reversible if you catch the gyno while it's still forming. after a couple months it will set in and be permanent, outside of surgery of course.
stop HCG before starting PCT. run clomid 50mg/d @ 4-6 weeks, alongside adex or whatever AI. start pct 4 weeks after stopping injections if it's test-e
25gauge for pinning, 22 gauge for drawing. those are ideal. 1 1/4th" needle length is the most you need for any location if you are below 15% bodyfat. if you want to do deeper injections that's your call but it's unnecessary. drawing needle doesn't need to be discarded, just the syringe and needle used for injection