Let me boil down the true reason of this thread;

"I want +20% fire resistance but not invest something to get that"
My answer would be; Nope.

Then tx3000 misses the point as usual, and the OP goes flaming and a large flamewar ensues over entirely a non-issue.
If you want to mention a "classlocked" slot think shields.

And look at that, Shield + sword wizard is even a perfectly viable option!!!

Get out of the 'class' mindset, out of the 'melee can't sneak too' or 'STR classes obviously have no use for INT' and many of the game's (lootsystem) so-called problems are shown to be not problems at all, but a large miriad of options for you.

Use the tools you have at your exposal, rather than demand the developers to change the tools for you, and in the process ruin another player's awesome fighter/rogue.