Crowns are in SS 6.4? I don't remember I've ever encountered it. I'm talking about paying 20000 to have my ruler crowned. I know it doesn't work but I still don't like the idea (especially with 2tpy when ruler may change quite quickly).
SS is 1tpy but I was always changing it to 4 or even 6tpy and it was working fine, I haven't seen any examples of game breaking traits. To be honest SS 6.4 is great, the only issue I've always had with it were stacks of AI armies. I remember my last SS game where I tried to reclaim Palestine as Byzantium and I had to face about 8 or more full AI armies, not to mention even more full stacks of other muslim countries just waiting at my borders. Now when I know how to change the recruitment of units I can try to modify it to my liking. I've reduced replenishment time dramatically and so far I like how it is.
Also for SS I can install Royal Ladies of the Court which fixes stupid vanilla marriages system.
I also like to focus on economy, not on warfare (occasional battles are fun, but speaking plainly - battles are not my fav part of TW games). On SS I can select more peaceful AI and relations work well so far - I have good with my neighbours so far and for example Portuguese living on the other side of the continent are not mad at me for some unknown reason like it was always in SSHIP. Also AI is not as warmongering - in SSHIP AI was frenzy, declaring wars like mad, there was an eternal cycle of truce and war between Sicily and Byzantium - they were declaring war, signing truce few turns later only to declare war on the next turn and so on for the 80 turns or more...
I think I understand the choices you've made (with no late campaign start many players would never reach late units at 4tpy), crowns add more depth and challenges etc. but I think that SSHIP not only fixes what I disliked the most in SS (army stacks) but also adds things I'm not too fond of. So it'll be better for me to try to eliminate those stacks in SS without adding anything else.
Of course it's totally subjective opinion and I understand that others may love new features of SSHIP, because you did a really good job inventing and adding them to the game through scripts.