I'm a protestant on the way to marrying a Catholic, and being exposed to Catholicism my whole life, I have to say the divide is not nearly as strong as people play it off to be.
Now first, I want to set some divisions down – basically all Catholicism south of the US is heresy, period. I went to a lot of masses when I was younger, the homilies were halfhearted at best, and it being a primarily Hispanic congregation we celebrated just about every backwards occult feast and tradition that exists down there. Santa Muerte and a lot of folk medicine and witchcraft is very focused in the Catholic tradition, and none of it gets spoken against too harshly by papal authority as far as I can tell. That's the big reason I distrust the current pope, although I was a bit fond of the one before.
Outside of South America though, the Papacy itself is probably the main issue most still have with Catholicism when they really think about it. Not the fact that he heads the church, but his quasi-divine status. The supposed inerrency of the Pope on spiritual matters doesn't really jive with historic reality, and it all just seems like deification of someone who should be regarded as nothing more than a man.
The issues of icons and veneration is the only other (Lutherans believe in transubstantiation afaik, although I personally don't see that in the context of the cited passage), and I think a lot of that is the fault of the aforementioned Latin and Hispanic Catholicism (although the various Marian orders over the years haven't helped). I've had some profound spiritual experiences in places like The Grotto in Portland, despite being of the persuasion Servites border on heresy, precisely because of that border between veneration and worship. I wear a Saint Benedict's medal, because while other medals focus on asking the dead for intercession (something I think is harmless, but don't buy) his is a powerful statement. Even if based on myth, the whole "get behind me satan" prayer is a comfort, and in my respect for the saint it does point my eyes upward. I wouldn't take that veneration so far as to recite prayers to those people, it doesn't sit right to me, but so long as I'm not made to do it, neither of us is made to stumble, so it's acceptable. If the church could divorce itself from the blatant idolatry of the South American church alone, I think it would be on much more amicable terms with the stricter bible belt of Protestantism.
That and avoiding the movements that want to elevate Mary to "co-redemptrix" and all that nutty shit. I don't think immaculate conception is a vital issue, but come on, she had other kids, you can argue around them being hers, but what's important is she was a normal mom. If she wasn't, it'd be unreasonable for Jesus to be held as a perfect example, because he wouldn't be representing perfect humanity. He'd be representing another, transcendent humanity we could not hope to emulate.
Short those big three though, the divide shrinks no deeper than that between Baptists and Pentecostals. Where I grew up they shared a softball team. The ins and outs of the theology differ in some respects, but Catholicism is just a megachurch that's been around a few centuries longer than Cornerstone. That's not necessarily a bad thing, but fostering so much division when there's so much alike just seems counterproductive. I live in a place where many of the bigger churches are vastly different in practice and style. It's uncomfortable much of the time for members of one to visit the others. We all share our young adult community. Sometimes the speakers are powerful, once in a while they're bullshit, but we always work it out together, and as time's gone on the churches have just gotten closer – socially and theologically. Idk why the Catholic Church can't, at the very least, attempt the same (besides pure stubbornness or complacency).
Anyways, hope that ramble is coherent, to bring it full circle these are all things my girl and I have discussed over the years. She's the one that got me open to the idea and intent of icons (still not the practice) in the first place, I'm the one that opened her eyes to the Hispanic problem (we live in a very Catholically white community, she has her whole life, I grew up in California). Together we've kind of reached a theological synthesis where we agree about most things, but I was curious if anyone thought the same way (if I'm not too disjointed, I'll clarify in the morning if I need to, it's almost 6 AM and I'm finally tired, but my brain died hours ago). Anyways, tell me why I'm wrong and all that and pick my brain, I'll respond when I can, I'm really curious.