I have to disagree w/ the 3 bolded statements. Not all nonCatholic Christians believe in the Trinity-Oneness Pentacostals don’t. They believe that Jesus is God, and ONLY Jesus is God. I think that falls under the heresy of Modalism (Jesus only being God, just assuming different roles at different times?), but their belief in the Divinity of Christ would qualify them as Christians, no? Due to that, the Holy Spirit, for them, obviously wouldn’t be the 3rd Person of the Trinity, simply Jesus’ spirit.
Not all Christians believe in the gifts of the Holy Spirit. Baptists (the more fundamental stripes, anyway), do not. At least, they don’t believe the gifts “are for today”, they think they ended w/ the Apostles (kinda like Apostolic succession and oral tradition

).
As for the 1st one, I think Sola Fida Protestants believe in grace, they just believe that the only way to
get grace is by having faith (alone).
As for the things we could learn from each other: Most Catholics could definately learn to read the bible more (then they’d realize that they hear it every day at mass

). NonCatholics could learn that “tradition” isn’t a bad word and IS Scriptural, as well as the value of redemptive suffering (and that it doesn’t mean Jesus’ sacrifice “wasn’t enough”).
In Christ,
Ellen