I think like a lot of people it's one of those debates, like Israel-Palestine, where you prefer not to get involved, because it seems like a mess of competing claims and counterclaims and historic grievances.
But I did spend a lot of time listening to the Troubles podcast on Spotify, presented by Oisin Feeney. I thought he did a good job of letting all sides give their accounts, and letting you empathise (if not sympathise) with everyone involved. Would really recommend it.
I personally feel as Ireland and the UK become much more similar, less religious, less sectarian, more liberal societies, the people who still want to fight to the death for Republicanism or Unionism seem a bit unhinged to me. I'm sympathetic to the non-violent, pro-compromise people on either side, and it's a shame the more fundamentalist, no surrender types are coming to the fore again.
Edit: and as to your original question. I don’t think many Brits, if they’re paying attention at all, have a lot of time for the DUP. They are so far removed from mainstream British politics and society, seem more typical of the US Bible Belt. Seem like the type of cretins Danny Dyer would do a doc on. But the old UUP were held in fairly high regard I think.