We are open to doing that, but what percentage down payment should we ask for in order to protect us?

Putting more money down to make something have a positive cash flow does not make it a great deal if the return percentage is way low.

Bear in mind that there's a flat fee on top (typically around €1,000 per year) so the added percentage will depend on your income.

I did not say that buying lists would not work, I merely referenced that lists from list brokers are sold to many many people and likely have very low success rates from a percentage standpoint. 

We bought a new home back then, with a variable rate, 40 year loan, with a starting rate in the teens!

Again, you should only counter if the reduction in price is justified by necessary repairs.There are many variables to consider and I cannot accurately predict, at least without knowing the circumstances of this file, what the lender will or ill not do.

This question is pretty hard to answer because it depends on a number of variables and what your goal is with investing. 70% of "ARV" minus repairs is what is often quoted for FIX AND FLIP projects.

I haven't gotten to tear through this entire site, but thus far it certainly seems to have a wealth of potentially interesting topics and participants (those that follow the rules and aren't banned, which seems to be a disturbingly high percentage of the posts I've seen thus far - is it that hard to not turn a post into an advertisement for oneself?!).

The percentage of real estate investors in the room at a monthly meeting is probably higher than you will find anywhere else. 

You would add to that the amount of capital improvements made on each of the two and then subtract the depreciation taken (using the same percentage allocations as the original basis allocation).So you're original "Gah" thought is probably correct.