using laptops as a forever-plugged-in device (regardless if workstation or server) isn’t the greatest idea. as an intermediary solution, like until you have something more permanent in place, sure. otherwise, look elsewhere.
limiting battery charge isn’t available on all laptop models and is aimed at preserving the battery’s functionality; it doesn’t solve the issue of a forever charged and never emptied battery. on the other hand, removing the battery on a lot of models limits their performance, significantly.
what is a viable solution is if you get a laptop board that runs at full power without battery, you can remove the board from the laptop, retrofit it with better cooling and additional storage (mini-PCI or M.2 to SATA adapters) and you end up with an energy-efficient server. but that requires a lot of work and is not something recommended for non-enthusiasts.
in short, sell it or swap it for something more adequate.
kodi and its derivatives are not something you should be using. it’s shit software on so many levels and we should burn it in the deepest volcanos we got.
try one of these:
run lineageOS TV (konstakang images) on it and install regular ATV apps for the services mentioned. so, like googletv except there’s no spying and ads and shit.
create a normal linux box that has a DLNA sink e.g. using macast. there’s no remote control, you use your android/iOS device to send it stuff, like movie from Jellyfin or a youtube video, and it plays it back and allows some control (pause, play, rew/ff, etc)
dedicated Jellyfin box; same as 2) but boots right into jellyfin client. it can be run in TV mode where it reacts to only up/down/left/right/enter/back, via gamepad or remote controller. if yours isn’t recognised, you can emulate it with InputRemapper.
not familiar with how twitch does stuff.
you also have the option of installing a normal raspi distro and then using a wireless keyboard and mouse/touchpad to run it, but I am of the opinion that once the device gets placed by the TV, it loses all keyboard and mouse privileges and should only be operated via the TV’s remote.