For most at this point even a Google enabled Android phone is a better option. You can always sideload apk and reinstall with something less Googlefied down the road. A step in the right direction is better than boot licking.

Depends on the phone. Most major manufacturers make it close to impossible to change the OS in many countries. Samsung is fully locked down here in Canada for instance. But as you said, I can load an apk and block their tracking at least.

IMHO buy an older model, and unlocked phone on ebay. In this case it is possible that the IMEI does not belong your country. But choose carefully, before buy, se the supported phones on the desired custom rom disgributions website. And if you a newcomer in custom roms, buy a cheaper one. So if you make a brick from the phone you easily throw it :-)