He sounds Ut to me and I think he is ready for some more A time. His first A time seems almost certainly too short and the rest of the day you'd say he is doing about 2h? I would try and increase it by 10-15min every 3-4 days. You'd need to be consistent, though, when increasing the A times and stick with them for those 4 days - that will prevent him from getting Ot and will give him enough time to get used to the new A time. If after 4 days you still get 45min naps then I would increase it again the same way.
But TBH, I don't think the problem at night has to do with his routine. My experience was that when DS was UT or the routine was off then sure, we had NW, sometimes really long ones, but not every single hour!
I do think that it's the co sleeping and the feeding to sleeping that is making it difficult. If you are doing the gentle removal plan then it's great, but just keep at it, because it does take time to work, like with anything else.
He is still waking up every hour at night even though you are not feeding anymore (or partly not feeding) because he has been used to that for so so long, so it will also take some time to get rid of this prop.
Hugs, hun, I know how hard it can be