Actually, I dealt with your second point, Pirke, in my thread on resources. In that thread, I said that a strategic resource should have a chance of first appearing in the game prior to the first tech in which it actually of use (in fact, my suggestion was that, if you go looking hard enough, then you should be able to find ANY resource, at ANY point in the game-it should just be a LOT harder and a LOT more expensive!)
Anyway, if you have any of that resource, then you get a bonus to researching any tech for which it is a requirement-and perhaps even a penalty if you DON'T have it!
For example: It is the ancient era, and your pre-iron age civilization is out seeking resources in a nearby hill/mountain and, after several turns, you strike it lucky and find a large source of iron (perhaps a size 8 lode). This lucky strike might give you as much as a +20% (or even +40%) bonus/turn to researching any technology that has iron as it's requirement-like Iron Working, as an obvious example! Of course, finding certain resources, like uranium, in the ancient age should be all but impossible-unless you find yourself with an OBSCENE amount of money to chuck away on prospecting for it! For example, you've just started a game, and you have a vast jungle to your north. Being a very cheeky player who knows that this is where uranium is most likely to appear, you decide to go 'fossicking' for it! Well, being the ancient age, you would get at least a -50% chance of finding it and, given the relative rarity of uranium, this would make it HIGHLY unlikely-if not downright IMPOSSIBLE-that you will find it, and you will probably just end up wasting a LOT of hard earned cash trying to find it! However, if by some miracle you DID find some, then later down the track, when you are trying to discover techs that require uranium, this lode will be very useful to you!
Anyway, for more about how I would like to see resources work in cIV-particularly in regards to research-then please check this thread:
http://forums.civfanatics.com/showthread.php?s=&threadid=86172
Yours,
Aussie_Lurker.