Boost works extremely well with a remote once sideloaded & updates via the Play Store after doing so.
As for Mail, I wouldn't know, being I haven't bothered/needed to install one on there.
Yeah, I can't understand why people want to be so limited in what they can do. I have a computer plugged into my 70 inch, 4k "monitor". Why would I want to go through reddit, have YouTube comments, or God forbid, an actual web browser. This is mainly in response to the other guy who said "but why?".
Any how, just side load things and see how they work. Probably not going to have much luck without a keyboard and mouse. Baconreader seemed to work fairly well on my old android rockchip box, haven't used it on the shield yet. You may also be able to sideload gmail.
I'm actually searching the sub for similar questions. If I load some apps and test them out tonight I'll let you know.
If you don't like the keyboard touchpad combos, I personally like the logitech k360 and the m570 for my living room/android tv setup.
But why