I liked your thoughts!
As for your questions, I don't think that Tony is like Robbie, i think that Will loves him, and so some of Tony's gestures mean more to him as a result. Think of that friend you know that smiles kind of weird, or walks goofy, or makes stupid voices. If you love that person, those things aren't weird, they're cute. That's what's happening here.
I really don't know what Will and Tony's relationship will be like. We're advancing about ten years to where Will would be in a position to really think about a forever man, and that's a long, long time at his current life stage. Then again, it's entirely possible that Will won't have a single true love, at least not for a long time. He's flighty with men, not unlike Stef, but he also knows that if he lets someone get really close to him (he's not letting Tony anywhere near that close right now), they could really hurt him. At least subconsciously, he's got to be worried about that.