looking at playing OSRS and new Runescape for the first time, maybe get to end game and get all steam achievements etc ,

curious if when i quit and trade my gold if i will get banned?

No you will be good

Go in grind and get that coin

depends how you go about it. you could get banned for RWT (real world trading)

but also, if you've never played either game before and you want to go for end game? jesus lol. Good luck.

highly unlikely, godspeed on them goals though gamer rise up!