Guardiola has a vision and mission for the treble winner at the moment they are facing Manchester United and winning in the early minutes, I think if they manage to win the FA of course they will target the UCL later against Intermilan, Manchester city really plays more pressing too seriously so it seems nothing is can stop them.
Guardiola made a good strategy to face every opponent that is in their way to get the treble winner this season, I don't think Intermilan can be seeded against Manchester City even though the Odds for Intermilan are very high and tempting because they have a chance to win because they are playing in the final.
I also think, that if nothing completely crazy and unforeseen is happening in the final of the Champions League, then Manchester City should not have to many problems to finally win this competition after being one of the best teams, if not the best team in the world of football for at least 3 or 4 years now. That being said, it is a final and only one game and there everything is possible. A lucky goal for Inter Milan after a corner or a freekick or something and then the whole game changes.
Also i think that Guardiola sometimes has the tendency to "overcoach" and overcomplicate things in very important games. I hope he just lets his team play as usual, then everything should be fine.
Actually they just need to play as usual to get what they want. But we also can't deny that the pressure will make their game change from time to time, and I hope they won't be affected by the big pressure on them. Being the favorite team to win the match they will obviously feel the pressure that is on their shoulders and I hope they can overcome it all so that everything goes as planned.