I have a Coilair myself from 2012. Since the bike does have some age to it, I believe you are stuck with the type of hanger you have and will need to find a derailleur that fits the hanger.
You can fit a 10 speed cassette on the bike.
I have used the front derailleur as a chain guard on other buke conversion and it worked out good for me. The narrow/wide will help bout you can still lose your chain if you get into some high speed rock gardens or jumps
Since you want to go 1×10 you may want to consider an oval narrow/wide chain ring Since your cassette can’t get much bigger the oval will help you a bit on power with your downward pedal cycle.