Have you tried copying cstrike.wad to the czero folder?
Yep the wad files I'm using do actually exist in their respective dictionaries.
Oh well, must be a quirk with the map editor then. Hammer 3.x doesn't like long filenames nor names with spaces. I would suggest you to use short paths, e.g.:
Seeing "\condition zero\valve\halflife.wad", I assume that Hammer doesn't even know on what drive the WAD is located, so look out for that as well.
The last thing I could think of is to create a new RMF file, and copy everything from the map to the new file. Hammer stores its texture configuration per-RMF, I think, so you could try that.
Now I got errors of entities outside world, propalaner ( Or something ) kind of plane and empty solids.
Yikes, that's not good when it happens. Press Alt+P to check for problems in the map, before compiling.
Hammer can produce empty solid entities if you removed brushes from an entity, while having "Ignore Groups" turned on. You could use the Map -> Entity Report list and find the solid entities, mark them and see if they're empty or not.
As for entities outside the world, I can imagine that either something went wrong during the .map file exportation, or you did something to a brush. There exist these so-called infinite brushes, which due to an error in the geometry, expand to infinity. Sadly, you'll have to delete those and remake them, since they can hardly be fixed in any other way.
Co-planar faces aren't too hard to fix, thankfully. These are two co-planar faces that would mean an error:
The compilers simply don't know how to subdivide this, so you just got to enter the Vertex Manipulation tool, and merge some vertices:
Hammer will ask you if you wish to merge the vertices, and say yes.
Lastly, Hammer is considered outdated by some folks. There are better, alternative map editors like J.A.C.K. and Sledge, and they're similar to Hammer, but way better in terms of stability, ease of usage, functionality and compatibility. J.A.C.K. is more similar to Hammer in terms of the UI, and I'd prefer it for more serious work, since Sledge is now in beta (used to be in alpha). But either way, both are more comfortable to use than plain old Hammer.