1. My BTC wallet will get hacked (unlikely, I'm securing my bitcoins rather well, on a separate dedicated machine). If this were to happen at the current rate, I would just buy the 100 BTC I owe people and pay everyone back, because my reputation and credibility is worth to me more than $1500.
2. If Event #1 (My bitcoins were stolen) were to happen and BTC vs USD will rise "too much" that the cost of buying back the lost BTC would be too much (my personal subjective value of "too much"), then I will default on the loan. For example, if 1 BTC would be equal $10,000 by December 1st, and my wallet was stolen, then I will not buy back BTC for $1,000,000, but rather file for bankruptcy.
What about 3) Pretend to have my BTC wallet hacked and keep everything?
Didn't we just have a major exchange pretend to be hacked?