New to bonsai...Bought this Fukien dwarf bonsai

Hello,

I've done a little reading here and have a few questions.

I purchased a small jade bonsai many years ago and set it in the window.  I didn't know how to trim it properly so just let it grow.  Over the years it got bigger but gangly and I wasn't sure what to do with it.  I set it outside and it's just getting bigger.  Should I try and trim it or just plant it in the garden?

I've missed having one indoors and bought what appears to be a healthy looking Fukien dwarf bonsai today.  It will get plenty of light in our Florida window and I'll keep it watered.  I'm wondering about fertilizer though.  We have hundreds of orchids and use Nutricote on them and am wondering if that's a good choice for this plant?  If not what fertilizer would be best?

It seems to be planted mostly in rocks although the roots are in what appears to be a ball of dirt.  I bought it from the person who planted it.

I'd like to keep this bonsai shaped.  Any tips would be appreciated!