A: Too reliant on MP for damage (To spam your bloody attacks, you have to spam your click button .... oh, what? It spends MP!???



B: Whips. I know its called "Whipmaster" but could other things be used? Such as ball and chain maces (would fit the mechanic quite nicely, on 1 hand you have the chain and on the other ..... a ahem, "ball". If not, then fine keep it simple with the whip.
C: Skills. I'm not an expert at the damage formula shenanigans, but I know it caps off at about 460% tip damage while non-tip damage is 30%. Why is this an issue? Because your stage-1 skills do damage based on NON-tip damage (excluding Dicing Whirl, as its a stage 2.) which equals crap damage, leaving you with only your click-attack, which again, drains MP if you maximize DPS and spam attack. Whirl skill tree is just ba---- oh right, I called ALL of them bad, lol.
D: Combat against bum-rushers, long ranged moving enemies - I don't think I have to explain this any-more, but: Hitting something with the tip requires aim or muscle memory, if an enemy(s) rushes you then congrats, you scored a bloody non-tip attack! Now the issue with the long ranged attackers .... you're basically forced to trade blows with each-other unless their attacks are slow as heck. (I have experienced this issue first-hand with Mandrakes, long range, heavy damage etc. Of course I could just purchase an entire Chivalry set that'll solve the problem! oh ... look at that price tag. The whirl is useful in the earlier stages for getting Tip Damage, but becomes obsolete when the monsters can just walk out of it (the first of these being the Logons. It'll still slow them down sure, but barely.)
Proposed solutions for each issue:
A - Inflicting non-tip damage now restores 1 MP. (Further increased with a theoretical new skill.) OR enchanted tip no longer uses MP, but also doesn't heal anymore. To stay true to it's name "Enchanted Tip", you get a 40% Attack & Defense buff up to the percentage of MP you have left (Level 1 starts at 10%, maxes at 40% depending on the skills level). Example: 180 is your total MP, and you have 90 currently, that means you get a 20% Attack and Defense increase, or a 0% increase if you have 0 MP (Skill Level = 4). (no decimals, so it'll go by 10% increments.) MP drain for sonic boom is simplistic, nothing really needs to be changed.
B - There is no solution, actually I should probably remove that, huh .........
C - Do not use non-tip whip damage as a damage basis/multiplier. Even 30% or less TIP damage would probably suffice, not sure how the damage from air burst/fireball whirl should be affected, but I doubt it'll matter much.
D - Tip hitbox, range, tip this, tip that. Would probably need new skills which can actually bind enemies in place (doesn't have to damage them, like the whirl.) If this would make them OP in PvP, which I doubt, then it should have a large MP drain (65+ MP starting from LV1.)
If you have any of your own suggestions for Whipmaster, post them below. If you think any of these ideas needs to be re-evaluated, sure post what you think I guess. I have seen utility skills being suggested, interesting all the same.
TL;DR - Whipmaster? MORE LIKE, WHIPCREAMASTER
(Whipmaster gets quite boring in the later stages.)