I'd probably build it in pieces, then cut the corners off each brush so they fit nicely against each other (and gives a cleaner cut than using carve) Takes longer but will be less messy..
Carve is comparable to the csg substract from the quake editor, it creates unnecessary brush faces when carving complex brushes. That will tend to increase compile time as well as eat up ingame performance.
Hallow isn't that bad, it just creates bad brush alignment. For example if you have a cube and hollow it, you will get some overlapping on the edges. As long as you move the edges out so only the corners are touching you won't get any unnecessary drawings.
I never had trouble with hallow also its save you time if you making a lot of rooms. It stupid not to use hallow cause it cuts your time by 10 folds. Carve is not as bad as you say it too. It too cuts down amount of time to make a little or big whole. It doesn't suck with cylinder either because then all you have to is move this spider vertices shapes back into squares that all.
I been using many different types of map editors and Carve and hallow are bar far the best to use cause they all the same in all editors, Even in Maya.