Hi everyone, I have 2 questions I need help clarifying and advice.

1. I drive an 02 wrx that has some synchro issue going into 1st gear, is it ok and should I mix 2 subaru extra-s + 1 quart pennzoil synchromesh + 1 quart redline lightweight shockproof fluid into my tranny. Is that ok to mix all that together? And should I?

PS: I want to try this mix before trying the scotty cocktail.

2. I recently got better at driving a manual car but I did stall over 80+ times to get to this point, so I was wondering if I should replace all the component that is used to start up my car?
If so, what are the components used to start up a car? Like ignition coils? what else?

Sorry I am pretty newb at this. All help and advice appreciated. Thank you