I do it with 50% ES, max telekenisis but no block (well, 14% but....) and ~70% FCR. I'd suggest the 63% FCR BP as it's quite noticable and you'll blast past more or less any monster pack unless meeting with a dead end. I'm using Suicide branch and Lidless for that and switch for Rhyme/MF orb when hitting Andy/Meph.
I'll give a few reasons why I do it with no block, allthough that's just personal preference - it's not better. Anyway, I like to have my vitality high because the real killer for a MF sorc is Mana burn packs. So, instead of having the shield/block as a hp Buffer when my ES suddenly dissapear, I have hard points in vitality. Also, if going questing and such, block does not save you from some of the worst hitting monsters in the game, like Vipers and Black Souls. Anyway, it's just prerefence as I said.
I prefer max block. There's no other way for me, but as double said, it's about personal preference. One reason for this, though, is that I like to use occy, and while I don't mind the odd teleport when meph hits me, it would just be too annoying taking all those extra hits that no (or low) block would give me.
Also you can block meph's cold ball, as it's half cold/half phys damage as far as I remember.
As for fcr, I like to meet the 63% breakpoint. I'm at 70 myself: Occy (30), Viper (30) and a rare fcr/mana ring (10). Getting over 63% really makes a difference, I think. I never really take any hits cause the monsters are too slow to react on me teleing by. Also a faster static and fireball is nice
The 63 point also gives your merc less time to strike things as you tele thru which is handy around dolls. It is also good practice to take his weapon away while in Durance 2 so even if he gets a hit off he cant kill one of those ugly guys.
My Sorc uses Wizzy, Viper and when in NM runs I swap Armor for more MF and it is totally freaking obvious how much slower and how many more things hit me or my ES or my Cold Armor, and how much my merc hits while teleing.
Get 63 and settle for no less while flying thru Hell, but I think you are fine in NM with good life with less and more MF.
I use my Merc as my Armor Mule, he wears my 1337 MF armor (discription not given) while I am in Hell teleproting around and if I want it I just swap my Viper to him when I give his weapon back at Durance three. My runs arent fast but I garuntee they are safe!
Btw.....OT....I have had this "terrible" string of luck lately. Now it isnt totally terrible, and actually starts off kicking but, but the last 5 times I decided to do some runs my first run struck it big and every follwing run was flat out poor!!! It isnt all taht bad as I score but it is rather strange.
Glacial (ownage skill IMO)
All Maxed with:
17 Hard in Telek
1 base ES
like 4 hard in cold ball or whatever the other synergy is
1150 life 900 Mana
Shako (just got)
Viper orf 1337 MF Armor
Rest in Peace (whatever)
+1 wiht FCr ammy and other goodies
She has base Energy and has a ton of small lifers, 6-7%, Gheeds and a grond or two Mana ones and has to toss her Keys to pick up a pole. This is my first ever character that I dedicated al my best resources to and I am happy with it.
All my MF really comes from Baba on switch and charms with a little on gear.
Oh she has max block also and the only thing that has taken here below 3/4 life is standing around iding items while poisoned!
I find that the 105 breakpoint is really really nice to have, if you can make it without significantly compromising your gear. Not only does it significantly speed up your runs, but even teleporting through fanta dolls, you're unlikely to get hit at all. My sorc wears:
Heart of the Oak
Stone of Jordan
rare 10 FCR ring with 5x mana and 14 dex
She's got 1386 life and 1190 mana. Str is 80 base, Dex is 40 base (needed more to use my Ali originally, were I to rebuild, this would get no stat points), 390 Vit base, and 35 base Energy. Only level 91 at the moment, but she's done her fair share of solo Meph and Baal runs. Max resists (well, except for poison, but who cares about that?). With items, her Dex is 102, giving her a whopping 19% block, which I don't find makes a difference at all. With level 1 ES and level 15 Telekinesis (so far) she can tank Meph and regenerate life/mana faster than she gets hurt.
With speed and a good life/mana pool, I don't find block to be necessary at all.
Anyway, I've done quite some Andy runs and just recently I upgraded them to Meph runs. I must say, Andy is FAR more frightening than Meph is. I have no idea why they did that, but Meph seldom (as in never) kill my HF merc, while Andy's punches (along with her massive poison) makes me want to heal him ever so often.