It eats up the amount of available space still left. If you have other games or DLCs for other games already installed, this isn't an option.
Well that is always going to be an issue of having a small hard drive, and there's not a lot I can suggest to remedy that, can you not get a bigger HDD for it? I remember back in the day 15 years ago or thereabouts when I first bought Baldurs Gate it came on 5 CDs and there was interminable CD swapping and long load times unless you had the internal disk space to do a full installation (and that was on PC when a 250Mb HDD was but a futuristic sci-fi dream), it's just one of those hardware limitations - loading off a hard drive will ALWAYS be faster than loading off CD/DVD. You have the same options I had back then, either put up with long load times or clear off space on your HDD.
PC user, with a monster machine and a RAID array for a hard drive.
I have a problem with laoding screens too- they disappear so fast I can't read the little tips and story bits on them.

Mate, as much as I appreciate your enthusiasm and like a lot of your opinions, there's no need to rub salt in the wounds of those having difficulties.... I too have a great rig that cost me over $1k (bought components for £850 GBP and built it myself, not sure of the exact exchange rate), but a lot of people don't have that luxury.