1) To access the context menu in Android, you either need to long-press using a touchscreen or press the “c” key on a keyboard.
2) I don’t know of any way to get those add-ons to play nice together. It seems like you just need to pick a side. :(
3) I’m not aware of any timer feature for Elementum, sorry. That would be a good feature to request of them.
4) Yes, I recommend and love Trakt. Read more about it here… https://kinkeadtech.com/complete-guide-ultimate-kodi-setup/#setup-trakt-tv-integration
5) cCloud has worked well for me in the past. The Crew does have a pretty comprehensive list of channels from various sources, so I might suggest disabling Indigo to hopefully get The Crew to work for you. I just tested on mine and was able to stream a live channel using The Crew.