If u prefer tank then u can change it. For dripped, just 5 to 8 drips should be good.. over saturating the wick might not give good vape.

I don't know what's the best tank BTW, I am using ithaka and vivinova for the meantime

Yeap there is  lot more. Vivinova is the easiest o maintain IMHO. Just that airhole is small and the vapor is less..

Dripper or tank with larger airhole is good to produce good vapor. But since u have rda mini, u should watch YouTube and see how others are getting good vapor.

Since its mechanical then any way u insert battery r OK.

On my chi you 1:1 the positive is facing top firing pin. If you are not sure of what you are doing, suggest you attend a vape meet and learn more from the experienced users otherwise you might overload the battery and there's a possibility of explosion if that happens.