Ask HN: How to build a business around other companies' ever-changing policies?

It's seems every time I begin work on a plan based on someone else's platform there is some disastrous change to the API, they block my account on a whim, or some other problem arises that destroys my startup plan.

Example 1: A product search engine. Before I had a working iteration, Commission Junction (who we were counting on for affiliate revenue) blocked my account. I had not even used their service once and could find nothing in the TOS to explain their action.

Example 2: I have an online store selling electronic parts and an AdWords account that I opened with a $100 coupon sent by Google to my inbox. I deposited $10 into the account as per the requirements of the coupon. I then started an ad campaign and was curious why no ads ever showed up on Google. After a while I contacted customer support and they told me my account would be shut down, without explanation. Once again I could find no violation of their TOS--there were no copyright words in my ads (other peoples' ads have the same words) and I never clicked on my own links (they were never up).

Example 3: A social wishlist startup. I spent days learning about Amazon's Product Advertising API, installing Ruby/AWS, and getting a simple Amazon Wishlist importer working. Today I find no mention of the API functions I was using on Amazon's site and I find out in a forum post that Amazon is turning off the crucial ListLookup and ListSearch functions (there is no other way to get at someone's Wishlist).

What do you do when you experience this kind of frustration with other companies services? They build powerful APIs and services, but I don't dare use them if they are going to be shut down or blocked. Should I only focus on startups that require no outside components to function until we're big enough that we won't be so dependent on these services?