LOL, I thought I'd shave a few inches off the waist line as well and a gun would fit fine....let's just say I was shopping for pants real soon. Hidden comfort type waistlines work really well for IWB.
Position for IWB is really a preference, and depends on the gun, body, holster, comfort, etc. For example, I carry my P229 around 4:45/5:00, while my snubby (If it's on my waist) at 3:00. It is just that certain conditions allow for better concealment and or access. When I bought my first IWB holster at gun store, the salesman told me where to position it, when I moved it forward to be more comfortable, he practically yelled at me for "wearing it wrong", thus I hated IWB for while b/c I couldn't do it right and be comfortable. i was naive back then....