Some Questions about DD and Reflection Mechanics

So basically trying out at building a DD build with Desecrate and my biggest fear right now is one shot myself because I blew up the HP Behemoth of a monster and reflect kills me. These next few questions are to help me understand what is happening and if my assumptions and review of other builds/wiki are correct.

First Question: Does the 8% of monsters hp scale with Fire/Elemental Damage buffs? Ex: If I got 200% Increased Fire Damage is it now 24% of the monsters hp as damage.

Second Question: Would the Reflect Damage be handled as such?
1.Check to Dodge (Phase Acrobatics)
2.Resistance Mitigation (88%-98% Corrupted Purity of Fire in Alpha's Howl and Rise of the Phoenix then if Ruby Flask is active for an extra 10%)
3.Lv 20 Arctic Armor takes off 189 Remaining Damage
4.Damage After this point would have 30% taken away from Mana (MoM)
5.Any Final Damage that gets through is taken from Life

Third Question: What is the avg HP of a level 80 Map's Monster?

Forth Question: With MoM if say I had taken 100 Damage and only had 5 mana, would I still only taken 70 damage or does the overflow go to HP and I take 95 damage?

Edit* Bonus Question: is a Critical Hit with DD amplify the Percentage based portion of damage or just the flat damage?

1) Yes, it scales with fire, elemental and area damage bonuses.

2) The unfortunate thing about DD is it doesn't deal spell damage, it deals secondary damage so it can't be spell blocked or spell dodged. So it's from point 2 onwards, the sequence is fine.

3) Doesn't really matter, we're dealing with percentages.

4) Mana absorbs as much as it is able, the rest goes to life.

5) If you get a critical hit, all damage a hit does is multiplied. Keep in mind spell crit bonuses won't work so it's harder to build DD for crit than a regular spell.

Much Appreciated answers thank you