Well, I don't know of a way to view ents in game. You can do textures with cl_drawtextinfo. You can easily check ents in a bsp file by using quark. It will give you all the info you need without the need to decompile.
Download:
http://quark.sourceforge.net/download.phpHow do look at the entities:
1. Open the bsp file in quark.
2. Click "open in map editor"
3. Click the "+" sign next to entities
4. Double click the entity you want to look at. Let's you change them freely, or completely remove them without the need for a separate ent file.
5. When done, go to file and click "close bsp editor"
6. In the screen that appears, click entities and remove the text "; worldspawn" from the top of it, or the map will crash.
7. Save, and you can now look up, change, remove, and add ents to any map without an ent file