I'm looking at an Ambassadeur 2500C and was wondering if I could use it for buzzbaiting on small waters. 

if you want to throw a buzzbait with it i'm sure you can but it's definitely not going to be the lightest setup

My main concern would be the gear ratio.  I'm afraid the reel would take the "buzz" out of buzzbait.    From a post by Goose, I gather they came in 4.7 and 5.3 ratios.

You can use a buzzbait /w line attached to a stick. You can use any reel for buzzbaits. Just depends on the gear ratio pertaining to how fast you need to reel. Slower the gear ratio, the faster you will have to reel to keep the bait up. 

Despite the lower ratio hearing your reel likely has a higher IPT than low profile reels of similar ratio. Give it a go and see what happens. 

Yes. 

I think I will give it a go!

I have no problem using Cavitrons on my Chronarch E5. 

Cool reel!  Definitely. I remember when 5:1 reels were "high speed!"

Well, I don't have the reel yet, but in the interim, I'll use either a Royal Express or a Quantum Energy Burner for it.