Thanks for fielding questions Mindflux

As I indicate on the preset page everyone needs to do their own enblocal. I am starting to remove them from all the presets and only providing a PDF file template. Just takes time to upload them all and since I need to update them to 305 I am doing it at the same time. Only done Vaermina so far.
Anyhow none of the GS presets use the proxy at all as I don't use SweetFX or any other injector with them as the instructions clearly outline on the page. I have a link to the STEP explanations on my comments section which, while not always completely accurate, do help a beginner with all the basics and a good place to read up on things. This page has all the stuff on enbloacl.ini:
http://wiki.step-project.com/Guide:ENBlocal_INIKeep in mind that depending on what binary you use there may be differences. When in doubt all you need to do is get a copy of the enblocal.ini default that comes with the binary file download and for the ENB preset you are using and then compare it to the one you have and update as needed. I personally keep a bunch of enblocal.ini files for each binary I use and give them simple names like enblocal_221.ini, enblocal_279.ini, and enblocal_305.ini. So if I use a preset that is using binary 279 I can just copy my enblocal_279.ini into the skyrim directory and rename it to enblocal.ini.
I do not recommend using ENB managers myself, especially for new users. It prevents new users from understanding how to install things and what to look for. Instead do it manually until you know how it works and what files to use. Then when comfortable use a manager if you find it quicker.
It is possible some files are getting missed in the install/uninstall.
My preset page has very clear instructions for installing and using a preset. Also if you using 305 binary you may need to change the THREAD section to match your set up. The link to STEP I provided will give the basics. Boris also has a NEXUS page with instructions and if you read the comments you can get some tips.
Spend a few hours of training yourself now and it will pay off later when you understand things and it becomes a lot easier to use presets. Well worth a small investment in time to read some things.
EDIT: Also I find a lot of people make spurious correlations between events when they are not really related. A prime example is people switch ENB presets and start to crash and blame the preset. Only to discover later that when they switched presets that also changed some mods and the mod changes created the crash or they did some other change on their PC that they forgot about.
Another great example - just the other day people all over started complaining about issues with ENB and SweetFX only to discover that Steam released a patch and those using steam overlay UI had their graphics with ENB screwed up if they also used SFX. Often there are other things going on that cause events and not just what looks obvious.
Of course sometimes it is also the obvious reason ... but if it was working one day and not the next ... well then something changed and it most likely wasn't the presets or the binary unless you know you were using a newly updated one.