Congrads! My A3000 is my favourite of all my amigas. I'm having plenty issues of my own. As long as you have 3.1 roms, which obviously you do, there aren't many upgrades short of the video card. That's what I am working on right now.
My favourite upgrade I made was my Budha Flash ide controller. And, that's not even because of the IDE controller, that's because of the A1200 style clockports that come on the card. I have a Subway USB adapter hooked up, and using all kinds of fun USB stuff, including a USB floppy, keyboard, mouse and cdrom.
I love this stuff!
Congrads on have 16MB of ZIP ram already in your machine. That's the biggest nightmare to deal with. LOL