Backtagging: By all means, yeeeeeesssssssss. Please don't hesitate to, if you want to.
Threadhopping: Go for it! Unless it's a locked thread, in which case probably not the best idea. Common sense!
Bending, breaking, or otherwise shattering the fourth wall: Yes, but again, common sense. Smallish things need no permission, but I'd rather not break his brain too soon into the game. Ask if you're uncertain.
Hugging/Kissing/Otherwise being touchy-feely: Yes, yes, and yes, but if you don't have his permission prepare for him to react accordingly.
Fighting/Injuring/Killing: By all means, fight! If you're going to injure, I'm probably okay with it as long as there's time to get him to medbay afterward. Nothing fatal, please.
Other: Use common sense. If it's godmodding, please don't do it. If you think you need to ask first, just ask. I'm pretty flexible.
As soon as he had a moment, Scotty - with his younger self in tow - nipped down to the transporter room to send his younger self off to Cardiff. And he was just grateful that he did have somewhere to send the kid, because otherwise he'd be stuck having to listen to complaints about not being allowed down to see the engine room all day. At least he was fairly certain the kid wouldn't be able to get himself in too much trouble in Cardiff. Might drive Jack and Ianto crazy with his attitude, which Scotty would have to make up to them later, but it was far better than risking the kid getting in an accident down in the engine room.
A couple minutes later, a tiny teenaged Scotty materialized in the tourist office at the Hub, and immediately started looking for things to poke around in.
Ten minutes, he'd said, and a little less than that he was beaming down into the Hub, just as he had about a week before - only this time for a very different reason. He didn't know what to make of the revelation that Jack was immortal, was going to live forever. But that wasn't what was important right now. There'd be time later to sort through that, to try coming to terms with what that meant. It wasn't that information that had spurred the decision to come down.
It was that Jack had been through so much worse than Scotty could even possibly imagine, and he'd had no idea what to say - and felt that this particular conversation was one better had in person, face-to-face. The silences wouldn't be so awkward then, when he didn't know what to say, because he'd be there, be able to hold onto Jack, to let him know that he was there even when words failed him.
He'd put it off long enough. The longer he waited to go apologize to Jack, the harder it would be, and the less he'd want to go do it. All he could do, really, was bite the bullet, get it over with, and just hope that he hadn't completely bollocksed everything up. He sat for a while, though, in his quarters, his PADD in hand, just staring at the blank screen. He wanted to let Jack know he was planning on stopping by, but....
But nothing. He had to do this. A few minutes of just sitting there, and he typed something up, and sent if off before he had a chance to change his mind.
Hey. I was wondering if maybe you have a few minutes. Wanted to stop by and talk.
It had been, Scotty realized, as he busied himself with packing up the now-finished phasers he'd promised to build for Torchwood, quite a while since he'd last talked to Jack. That was nothing new, of course - the two of them tended to go for stretches at a time without checking in on each other. And that was his first mistake - he ought to have called ahead, to let Jack know he was coming down to the Hub, but since it had been a while, Scotty thought he might just sort of pop in. Surprise Jack. There was of course the risk that maybe there'd be something going on with the Rift when he beamed down, but he figured that surprising Jack was more than worth it.
So with his shift over, and him freshly showered and dressed down out of his uniform and carrying a case with several non-regulation phasers he made his way to the transporter room and beamed down into the tourist office section of the Hub - the coordinates of which he had by now memorized.
Two hours wasn't really a very long time to wait, though the paperwork Scotty had to do in the meantime made it feel like much longer. In all honesty he probably could have gotten away with putting it off, but this way at least he knew it would be done. And for once, he didn't try to stay a little late when those two hours were up - he'd been told to keep taking it easy, for one thing, and for another, he had a visit from Jack to look forward to.
The minute those two hours were up, he sent a message to the other man, asking if he was ready to be beamed aboard the Enterprise.
[Scotty's in his quarters, sitting in bed, his left arm all bandaged up, and he looks a little spacey. Small wonder, considering the painkillers he's on because he's a total baby when it comes to being hurt. He's finally convinced Jack that he really really needs to let everyone know he's alright, although he's definitely looking like he could use some more rest.]
Um. M'alright. [He pauses, having lost his train of thought.] Um. So if you saw th'thing. M'alive.