Enhance doesn't use docker containerization anymore.
You should ask bitninja about pricing/features, this isn't the right forum for that.
OLS is pretty well supported, but it has issues, you should search the forum and read the threads, many recent threads will get you up to speed on OLS limitations. ELS is really good.
Theres limited integration with enhance/cloudflare, it doesn't work the way you would hope, it basically just syncs whatever dns records you put it enhance to overwrite whatever is at cloud flare and that's all - manual setup on per site basis, no automatic anything.
You can run any kind of apps. Autoinstaller is limited, but you can easily manually install anything.