Is a master link ok to use for a 1/8 chain? I know a connecting pin would be stronger, but is there any reason not to use a master link like the one below?

https://www.amazon.com/KMC-Z410NP-Co.../dp/B004JKJLU2

Also, I'm looking at buying a chain tool to replace the chain on my 7 speed rear mtb. Got a 10 speed rear on another bike, and fixed gear with 1/8 chain also. Would the Park CT 3.2 work for all 3 bikes?

Dave