It's not illegal to crack a game you own.
Technically it is against the EULA to alter the game's .EXE in any way, so unless there are laws that counter this, you can't crack games. On the other hand, making an image of a disk probably falls under making a copy of it as a backup, so you're free to do that. the status of mini-images is less clear, but they are probably an alteration of game data and thus against the EULA.
Also, publishers hate cracking because nearly all cracks are used for illegal copies. First of all, research indicates there may be as much as ten times more illegal copies of games then there are legal copies and secondly pretty much all illegal copies require cracks, meaning that even if all legal copies were cracked, 90% of the cracks would still be used for illegal purposes.
Also, there are many clauses in the EULAs that look very scary, but in the end are there for very sane and mundane reasons. For example, companies hold the right to alter the product without further notice and without the user having a say in it. This seams scary, but if it wasn't there they could never patch a product without tracking down every last user and ask them officially if they agree with the patch changes (which would get VERY messy with patches that repair loopholes people use to cheat at on-line games). Another one, the right to end the license is probably only legally invokable in the cases of cheating for on-line games, the distribution of illegal copies or usage of the program to hamper the companies financial status (relevant in the case of Gausian, which provides the source code on the condition that you do not in any way disclose this information to potential competition of the designers)