Confused about various addons

Okay, I need some help figuring out what addons I should use and what version. (I also have a question regarding npcs and the physics gun)

  1. I like Dismemberment Mod, however it is very buggy. I have been using the SVN version of GibMod, but I also want to know what the differences are between the numerous versions and forks of Dismemberment Mod, GibMod, and GibSplat, and what is the latest official version. Also, is Dismemberment Mod still being worked on?

  2. I am using the Achievements mod by RabidToaster. It works fine, but apparently he stopped working on it. There are now numerous forks of this addon, and I’m not sure which one is the best, or the most used.

  3. I have Advanced Duplicator from the Wiremod SVN installed, but I see something called Advanced Duplicator 2 here on Facepunch. Is this the official “version 2”, or just another fork?

  4. Okay, so I seem to remember being able to take any NPC and kill them with the physics gun by smashing them into a solid surface, but I cannot seem to do that now. (To be honest, that was one of the main reasons why I actually decided to legit buy GMod.) Has this ever been possible, or was this a GMod 9 thing, or is there an addon to do this?

Now, just some quick questions: Is there a portal gun, can I use binds other than the numpad to control wheels, thrusters, and the like, why do the npcs have decent faces, but shitty details on the clothes (even with mat_picmip -10 and every texture setting high), is there a way to make gmod use the custom textures i have for other source games installed, such as for team fortress 2, instead of reading the ones from the GCF?

Sorry for being text heavy, and a bit noobish. I am not an idiot with Source and the way the addons work and shit, I’m just new to some of the more complex components of the addon world.