HEVC (H.265) - Profile? Level? Tier?

Hello, my goal is to encode a 10-bit depth file with as much space-efficiency as possible (for archival purposes,) and so I am interested in HEVC encoding.

According to https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding#Profiles there are different profiles, levels, and tiers available for HEVC, and they correspond with options within AME's Encoding Settings panel. Can anyone clarify the following:

• For profiles, "The Main 10 profile allows for a bit depth of 8 to 10 bits per sample," but doesn't seem to guarantee 10-bit depth encoding. How can one guarantee the result is 10-bit?
• Also, "The Main 4:2:2 10 profile allows for... 10 bits per sample with support for... 4:2:2 chroma sampling" (as opposed to 4:2:0), but Main 4:2:2 10 is not an option in AME, correct?
• For levels, the article says "A level is a set of constraints for a bitstream," and outlines what bitrates each is capable of encoding. Why should one not simply choose the highest option, Level 6.2, and set the desired bitrate? Is there a benefit to choosing the lowest level that is capable of encoding the desired bitrate?
• For tiers, the article says "The tiers were made to deal with applications that differ in terms of their maximum bit rate," but I don't understand how to apply that. Should I just go with High tier if I'm going to eventually work with these files in Adobe Premiere and DaVinci Resolve?

Thanks!