I started my second character with the same set of mods I am using with my first character (minus a couple of mods which I realized were too much script intensive and I am forced to keep on using on my first character), and the first savegame just out of Helgen after the tutorial is already 4.780kb (compared to the 9.500kb of my first character with 80 hours in) - Now, I know that is not considered "bloat" as of yet but I wanted to ask, is that too much for a starter savegame in your opinion? Do I have too much going on mod-wise?

I have two saves from RIGHT before the imperials ask you to, "Step forward prisoner." and you choose your race/appearance. Both are almost exactly 4mb (about 4,050kb) and I doubt they grow much when you run through the keep, so I'd say 4.7mb is quite a bit larger. Not sure if that's bad though...

So, you think it's fairly standard to be around 4/5 MB at the start of the game? How many mods you had on at that point?

Hmm I'd say nothing to worry about, really. All my initial saves are around that size. As a rule of thumb you don't have to worry about the save game size per se but you DO have to worry when its size is increasing quickly. That's a good sign of save bloat coming your way. Here's a rough test: take note of your save size, run the game, type tmm 1 in the console to enable all map markers, enter a dozen of different dungeons and exit immediately. Once you have visited a bunch of dungeons enter a random cell, wait 241 hours, enter again one of the dungeons you have visited before, then save into a new slot and compare.