Newcomer to alpine linux trying a fresh installation

Hello everyone. This is my 1st thread on alpine linux forums, so please bear with me. I have been a debian user for the last ~10 years, so I can say I am very familiar with it and I know it in depth.

I first tried alpine linux on vmware when 3.5 came out and I was really impressed. I was looking for a linux based os to replace openelec on my x86-only machine because openelec is x64-only since early 2016. Thus, I am looking for the bare minimum (x86) installation (plus samba, ssh and some extras) which will run kodi properly. So far, I have managed to do the following:
- install alpine (setup-alpine)
- change repositories to the "edge" version of alpine
- instal samba (not yet configured)
- setup ssh (openssh) with root access
- install xorg (setup-xorg) plus the driver for my gpu (i915)
- install acf with the acf-samba and acf-ssh addons
- install kodi, alsa, wpa_supplicant, wireless-tools, the b43 non-free firmware (for my wlan adapter), util-linux (for autologin with agetty), bash, shadow (for changing my shell to bash via chsh), ncdu, nano, htop, cpufrequtils, lm_sensors and mpv (to listen to my favorite web radio while working on the tty)
- connect to the network wirelessly on boot, via the wlan0 configuration on /etc/network/interfaces and on /etc/wpa_supplicant/wpa_supplicant.conf
- autologin to root user with agetty
- start kodi-standalone as a startx session, via ~.xinitrc
So now I have a system which autologins the root user, I type startx and kodi shows up and works like a charm!

Where I fail and I have no clue why or what to do
- Network configuration via network manager. The system will not be on one place all the time, so it will have to connect to multiple wireless networks, so I thought of network manager's ncurses ui, nmtui. The problem is it only shows my wired interface, not the wireless one. Why? Needless to mention that, when trying, I comment out the wlan0 entries on /etc/network/interfaces and that the network manager service is running.
- A way to startx or kodi-standalone upon login, but only ONCE. I tried the ~/.profile way but, If i log in from tty1, it works as it should. If I log in from tty2 as well, it starts again.
- A way to shutdown/reboot the pc from within kodi. Selecting one of these options drops me back to the tty, exiting X and no shutdown or reboot happens.

That's all I can remember now. Any ideas on these will be greatly appreciated. And please move my thread if I opened it in the wrong section. Thank you in advance :)