I have lately had serious framerate drops with characters with more than 10 hours of playtime. I have also experienced A LOT of graphical problems lately; textures not loading, ground completely missing etc. I still have 1.4 because I cannot stand the ranged killcams. They ruin immersion completely for me, so my question is: Do the patches fix these problems?

I've not experienced those problems your having, but you could try the following, to see if patch 1.7 solves these problems for you...

Copy the 1.4 title update onto a USB drive or other device (just move it from your HDD), then download patch 1.7 to your Hard Disk (it is possible to have multiple patches available on different devices, as the Xbox will only load the latest patch it finds across all connected devices). Play the game for a short while with patch 1.7 to see if those problems have cleared up (one big fix is the Nirnroots, which causes all kinds of problems). If you end up not liking patch 1.7, then you can delete it and copy your patch 1.4 back onto your HDD. Just remember to create 'new' savegames for the duration of playing patch 1.7, as those savegames wont work with patch 1.4. That way, if you do roll back to patch 1.4, you can return to your old savegames.

Edit: Actually, I do remember months ago on patches up to 1.4, I sometimes had large squares of water missing, and sometimes chunks of background missing. But since 1.5, I've not experienced these particular bugs. Are these the kinds of problems you have had?