First, you're claiming that Overheat is going to scare away the pink blobs and put pressure on them. Well, that's not true in the slightest. Chansey and Blissey are going to shrug off a pathetically weak Overheat, Softboiled, and you're right back where you started. Hell, they can even take the opportunity to set up SR, use a status move, or Wish while you're busy switching out to recover from your attack that did next to nothing.
Bulky waters aren't going to switch in to Rotom-H, so I have no idea why you're pretending they will and then telling us that Electric is super-effective against Water. The stuff that is actually switching into Rotom-H is going to wall it hard or threaten it out.
Terrakion does not 2HKO Rotom-H, it OHKOs Rotom-H. Have you forgotten about Stone Edge? That's a clean OHKO on the proposed Rotom-H, regardless of whether Terrakion is CB, LO, or Scarf. Not to mention, Rotom can't do squat to it, especially if Sand is up, which gives Terrakion a 1.5x boost in SDef.
From all of this, I still have no idea where you get that Rotom-H puts pressure on the opponent. I don't even see why you'd want to use this thing over another Rotom form. Fire-Electric typing is trash, you shouldn't be weak to Water when that's one of your main targets.
Can we use good Pokemon please?
About Terrakion 2HKOing Rotom-H; sorry, I did meant to say "OHKO".
And Overheat is not going to scare away the pink blobs; I never said that. What I am saying is that Overheat is going to open a massive hole on them. You can just switch out with Volt Switch, but the pink blobs must think twice about giving a free switch to my Terrakion, for example, especially if they don't use Softboiled, as the next time they are going to be 2HKOed by Overheat.
About bulky-Water-types switching into Rotom-H, it's obvious that they are going to do this unless in the most desesperate of moments; that's where you have to lure them. The calculations that I've posted just show that they also take massive damage from Overheat; many bulky Water-types must think twice about switching-in if they aren't specially defensive.
What I want to say is that Rotom-H is like, for example, Choice Specs Politoed, this thing can, with its STAB alone, do massive damage to things that resist its STAB. Of course, Rotom-H can't summon its own sun...
Sorry if I am overestimating Rotom-H, I made a sun team with him a few time ago and I got impressed with the results, Rotom-H is not perfect nor the most powerful sun abuser but I don't like when people say that it isn't good.