Nope.
Yes it is possible. You just need to flash an ATV rom. Here's one I found with a quick search. https://forum.freaktab.com/forum/tv-player-support/amlogic-based-tv-players/s912/others-aml-s912/firmware-roms-tools-by/741250-rom-nexbox-a1-leelbox-q3-7-1-2-atv
Unfortunately not but you can get any of the following certified Android TV devices to save the hassle:
Certified AndroidTV/GoogleTV boxes for the US only:
- AirTV Mini
- AT&T TV
- Tivo Stream 4K
- T-Mobile TVision HUB
- Verizon Stream TV
Certified AndroidTV/GoogleTV boxes for the US and the rest of the world:
- Chromecast with Google TV
- Dynalink TV Box (Available at Walmart)
- Ematic Jetstream (Engel EN1015K for Europe. Available at Walmart)
- JBL Link Bar
- Mecool KM6 Classic Edition (Prime Video only. 10/100 ethernet. AV1 hardware decoding. 2GB of RAM. Available at mecoolonline.com )
- Mecool KM6 Deluxe Edition (Prime Video only. Gigabit ethernet. WiFi 6. AV1 hardware decoding. 4GB of RAM. Available at mecoolonline.com )
- Minix Neo T5 (No Netflix/Prime Video. Gigabit ethernet. Remote control doesn't have a microphone)
- Nvidia Shield TV (The most expensive but powerful)
- Xiaomi Mi Box S/4K
- Xiaomi Mi TV Stick (1080p only)
For more info about all certified Android TV devices, head over to Android TV Guide website.
Not possible.