The fees will remain low in terms of fiat value assuming that if the price goes up, activity goes up due to Monero's adaptive blocksize. See https://monero.stackexchange.com/questions/12729/when-monero...

Regarding the speed, many believe that instant / unconfirmed transactions are safe for day to day activities up to 10000USD. It's very difficult to double spend or inject numerous conflicting malicious transactions in hopes that the victim sees a legitimate transaction but a fraudulent transaction gets mined.

Regarding the ease of use, have you tried featherwallet.org or mymonero.com for mobile?