Why would you want harpoon root in a PvE situation? In PvE if you harpoon something to you the moment you smack it with Stock Strike, or hit Explosive Surge (or insert your attack) you should have enough threat on the target that it's not running away. In the case where that doesn't happen, it's normally because the damn thing cannot be harpooned to you. This is a waste of 2 points in PvE especially when stealth scan doesn't do anything for you in PvE. I sometimes have forgotten to switch to a PvE build when running flashpoints, and I'll tell you that Stealth Scan root is useless in PvE.
If you're absolutely wanting some PvP utility you should change your build because Neural Overload is something you'll want in PvP. Also in PvP Frontline Defense can be super-important (in my limited experience I've found it an almost absolute must), with it you can make sure healers don't get their heals out.
Your last build I would personally not use, dropping Steely Resolve means you drop damage, dropping damage = less threat. Which makes you a bad tank. Tanking is tough because you need to do 2 things, you need to hold threat and not die at the same time. So you have to balance between both damage and durability. If I had a choice between dropping Steely Resolve or something else I'd drop something else, like a point in Static Surge and a point in Shield Cycler.
I know I'm going to get a lot of flak for saying Shield Cycler, but in all honesty 50% chance to generate an extra cell . . . if you're already getting Energy Blast your ammunition management is so easy especially when 1 point in counterattack gives you the same shield chance benefit. That being said this decision is also somewhat gear/style dependent as well. Is your gear good enough that dropping 1% in shield chance is not a big deal?
Though personally I think that this build won't do well in PvP, in PvE I'm not sure because I run a very non-standard build and I really have no idea what your playstyle is like.