I am looking at the T3 Subsystems BPC Skills and I see that (for example) Defensive Subsystem Technology only needs level 1 for me to be able to invent. Is there any gain or advantage to train these higher than 1?
improve chance of success per Invention - EVE University Wiki
The effect of skills is equivalent to 3.333% per science skill level and 2.5% per encryption skill level.
yes, very important.
Time is money, the more you can research the more you can research right?
Over a year if your maxed and there are some nice implants for ME, TE etc as well, you are going to be turning out more research by far than someone that isn’t doing that.