To be fair mate I haven't met a single Spurs fan who thinks playing at Wembley will be a cakewalk, I'd say to a man Woman and Child no one is actually looking forward to it, maybe the new season ticket holders hold a bit more of a buzz than more longer term ST holders for obvious reasons. I also hold some reservations, although most of my negative vibes are what the crowd will be like more than what our players will achieve, although a run of decent results will boost everyones (supporters/team) confidence and would be most welcome.
I get your pessimism, your post reflects this, but you could have mentioned Juve, or how about Man City, who also had a very successful season at the Etihad, finishing ninth having in their first season in the PL after their promotion? It's like you committed these to paint the blackest picture you could. These are positives that have happened since moving into a new stadium, which makes them just as relevant as the negative ones. Acknowledging them at least provides a bit of balance and may be something positive to cling onto, what is wrong with at least doing that?
With respect the other clubs you benchmarked were West Ham, Brighton, Charlton, Woolwich and Coventry with the exception of Woolwich (who's first season at the Emirates wasn't as disaster as they finished in the top 4, in fact there wasn't a drop in form as you and the press are saying they were 4th at Highbury and 4th in their first year at the Emirates, which kind of indicates to me no drop of form what soever, they also were runners up in League Cup) The other teams were absolute dross when they made their move. I like to think we are a better team than West Ham, Charlton and Southampton and we are perhaps closer to Woolwich at time of moving. Being a good side means you stand a good chance of doing alright, as opposed to being shit and doing poorly because you are shit.
We can't do fuck all about moving to Wembley, so I'd rather search and cling onto any positive I can possibly find, it makes me feel better.