I mained a Wiz in classic and occasionally played several other casting classes. Play a wiz here.

From what I recall the resists and fizzles were lower on live. I'm not trying to base that on believing I can remember even and yellow cons resisted 'X'% versus the % they resist here. But on how my playstyle differs. On live given the choice between killing a yellow, white, or blue I almost always chose white or yellow because for roughly the same amount of mana I would get more xp. Higher lvl mobs had a few more hpts but they weren't much more difficult for me to kill.

What most people say is that resists get better as you level. I think its more of the case that mobs more levels down when you get higher are still blue. Which was the same as on live. On the other hand some specific mobs are less resistant than I recall them being.

On P99 I feel like spells are treated a little more like the melee mindset where fizzles and resists should be fairly common like misses. In my late 30s I still felt like I was getting a fizzle every other mob on finisher small nuke which I had for over 20 levels.

As far lifetap goes on live there was a -200 resist modifier so it was nearly guranteed for normal mobs while leveling. Can't really say for fear.

I guess you can't expect everything to be exactly reproduced. I went to kill a Gnome in LFay that I remember being easy xp and re-read accounts of on alla to confirm. Multiple posters claimed they could two shot the NPC because of low mage hpts with two sub 500 hpt nukes. It took me about two and half 600+ nukes to kill her on this server.

Back on live Invoke Fear seemed to work better for my SK. I don't know though, maybe it was crap too.

As mentioned some spells have modifiers (Heat Blood series, Taps, etc). Fear I'm sure doesn't have one or might even have a penalty as the effect is pretty amazing.

After leveling a Rogue and SK in live and now a Necro on P99 I think the resist rates are just fine for them, or at least not noticeably bad. Any easier and it would be hard to call it, "gaining experience" ;).

Spell resists are very level sensitive here, much more so then I believe on soe. This can work for you (root regularly holds for full duration on a low-blue mob) and against you (accidentally pull yellow mob, it then resists 5-7 spells in a row and kills you).

Personally I prefer it, you have a better idea of when you can rely on spells and when you cannot.

It's when Velious rolls around enchanters will start hurting, very high MR if not out right mez immunity is the norm. Its a rough expansion for them.