I've advanced quite a lot now (thanks cyclone for the worksite shutdown), you were right, the despawning enemies has not caused an issue with leveling and I am seeing as a reasonable decision to make the game easier for some. It certainly makes boss approaches easier.
That being said, bosses have been pretty easy. I think the only one I had difficulty with so far was the
and that was partly due to the number of enemies I faced on my way to them. Also, I was pleasantly surprised to see an old friend in the Blue Cathedral. It was funny because I thought the Cathedral looked like Anor Londo and the specifics of the building design looked out of place against the other parts of Heide's Tower.
I am now in Earthen Peak/Harvest Valley. I feel I missed a good portion of Harvest Valley because of the poison, so I am sure I will need to doubleback there. A question for the first boss in Earthern Peak, could I cut his tail? I was trying to because he looked like something you definitely could.
I haven't had weapon degradation issues anymore and have been using primarily the craftsman's hammer and the halberd. Haven't upgraded any weapons yet because I am ripping up enemies and bosses without too much difficulty and hammer weapons seem to be the best thing in this game.
I don't know if this is just SotFS, but I am really enjoying the level design, layout and enemy placement. I feel it is streaming me in the directions that would work best for my stage of the game while also giving me a taste of what would be in the other direction if I want to face a challenge.