How many keywords are ok in AdWords?

I have a local business and I'm targeting all the surrounding areas. This includes surrounding city names, and their zip codes in various combinations with keywords I'm targeting.

As a result i have about 6,000 keywords im currently targeting.

Is this ok? Am i oversomething here? Is there a limit? Can i go for 100,000 keywords?

You need to target better. Take a look at ppchero(I can't link yet). They recently had a blog post which had a good strategy on how to organize your campaigns.
Don't forget that campaigns take some optimizing before they start to give a positive ROI.

My ROI has always been positive for my business, even when i simply used the adwords express stuff for my google places page. ROI has always been positive.

The only problem is that it's slow. I get 1-2 clicks from my area per day. And my conversion rate is like 20% so i get a customer once every few days. The ROI is incredible, the volume is just ridiculously shitty.

Google doesn't even use 50% of my daily buget. So I'm trying to add thousands of relative keywords to "scale up".