1st off I need a tooltip mod. I just want one that is highly customizable. Also, in the chat window, I reamber Mazzle had a Add-on that if you clicked on a item, you would get all kinds of info for like prices, and drop places I think. I also, need a small casting bar. One that I can move around and also has the targets casting bar.
Engravings lets you have places you might find items appear on the tooltip, Mendeleev also puts extra data there (although not locations I believe) and Sellfish gives you vendor prices for things (if you get Sellfish I also recommend Vendorbait as it highlights which quest item is worth the most money - very useful! All of these are available here.
Quartz is the most customisable casting bar I know of (files.wowace.com again). Having said that, a lot of UnitFrames addons come with builtin castingbars these days.
Except that the DogTag library has simply astronomical resource usage. If you can avoid using it, I would highly recommend doing so.
Currently I have only one addon that uses DogTag: InfiniBar, which uses it for customizing keybind text and button highlights, for some reason. As I'm looking right now, DogTag alone is averaging 4.7 CPU/sec.
For comparison, I am running a total of 158 addons (including libraries); my addons in total are using an average of 12.5 CPU/sec -- that means that DogTag alone is using 37% of all the CPU time used by 158 addons, and that's with only one addon using it for very minor tasks. If I disable InfiniBar and DogTag (and Rock and the other libraries that are only used by IB), my addons in total are using 3.9 CPU/sec -- less than DogTag alone.
CPU usage is by far the biggest impactor on your game's performance. For s***s and giggles, I just disabled the InfiniBar crew, and staring at a wall got 141-147 FPS. I re-enabled InfiniBar and its libraries, and staring at the same wall (I didn't move the camera) I got 133-138 FPS. I can only imagine the greater difference if I were using addons that used DogTag more intensively.
In short: if you don't need the level of customization offered by DogTag via CowTip, don't use it.