Bad builds IMO.
UB is far stronger going Ooze and Foul Grasp. You can then drop Spit, need no mana item and can get more health. Hotly debated, but usually far stronger, the only exception being against a kiting Regulus.
Regulus with stats and mines is also a weak build. Mines are easily countered by good players, don't walk over them or move on animation. Scope 2 and 3 are junk for a skill point, simply not needed. Better off getting Mines and Snipe. Also, with all your snare skills, with the new patch they are wasted as you can only reduce to a maximum of 33% off base.
An ice TB with no Frost Nova? That is a pretty interesting build, personally I think you are better off dropping Deep Freeze, and going Frost Nova, which is far more useful to you and your team.
Rook I don't know as I don't play.
Sedna, hmmmmm, I think your mana requirements are too high, to be successful with this build and your recommended items. Might be ok though, and looks absolutely standard.
I understand the idea to go low on mana items and stack health. However, two of the DGs TB and Reg, rely heavily on mana and you are likely missing out a lot of damage and useful skills. With careful use of skills you can still maintain mana levels in combat.
Also, with starting items, Scale Mail is a pretty good choice too, better than scale helm. You can take a 200GP combat mana potion for extra mana.