I think what they meant regarding the mastery tree is that you pack all your points into one tree and do not consider anything else and this leads to a one-sided champion. Also, I think you do not need Tough Skin and Bladed Armor on a non-jungling character.

Regarding TF: I usually purchase Sheen first and then buy other things, as Sheen is the crucial component for Nasus that adds damage to your Q. It might be bad to rush it because it is so expensive. Yes, it gives good overall stats, but I think that a Philosopher's (before Sheen) and some resistances or health before finishing TF are better. Guardian Angel might also be better when you buy it later.

Maybe you should consider getting some CDR items as well as it really improves your Q farm.

I agree that your guide needs coding.

I appreciate the feedback but before i change everything can you tell me 1: why is it a bad idea to rush TF? (i've done it literally every game with some great results) and 2: why is the mastery tree ineffective?

don't rush tf. Learn some bb coding from jhoijhoi's guide. It's a wall of text.
Though it's not those random hecarim stuff.. so +1 :P
You lucky boi.
Jk, kinda.. but i fink u haf potential to make this a great guide! +1

Rushing TF on nasus is a huge no no. Along with having a skill build that teeters on ineffective and a mastery page like that, I'm going to have to say no to this guide.