I have 2 suggestions.
1. Offer some form of minor reward for people who donate. For example: Someone donates 25 dollars they get a pack for one character containing a book with some XP. Nothing extreme, perhaps 1,000 xp. Another option is some Caps, or a perhaps a Starter gear pack for higher donations. The pack might contain a 10mm pistol, some ammo, a few stims and a Combat Leather Jacket. Another option is some form of temporary immunity to player attacks in the wasteland, This would be both ways so you can't go on a killing spree, but also you can survive without some group of noobish pkr's dropping in on you and blowing you away just cause you're there. I'm sure people may have other suggestions for rewards. But nothing too big. Even if you donate 200 dollars you don't get a Hardened Power Armor. (Also I didn't see a way to change it, so perhaps a donate link that goes to a page with English on it.)
2. Do NOT implement in ANY WAY, the Tracking perk. It's bad enough in the game to do ANYTHING alone or in a small group, let alone if you give the uber hard cores a way to find your tent and base. They could spend hours eating up your Mercs when you might be offline and then guess what all your hard work *poof* And your reward for all the playing you did? A swift kick in the ..*spleen* I mean we're not even really safe in the so called "Guarded" towns. You think if someone has a chance to find you anywhere in the game you'll ever get to do anything?