Been a while since i've looked at an ABG so might be a bit rusty, but since no-one else is biting i'll have a look.
1.) Yeah, a bit iffy. I would go with metabolic alkalosis with respiratory compensation as the pH is 7.45. The important thing (in real life at least) is to know what information you need to decide between the possibilities. For instance time from onset of symptoms could help in determining which it is as metabolic compensation takes longer the respiratory compensation. The are also clinical tests which could help determine which.
2.) Agree. It is weird though that the CO2 has risen so quickly. Think there is something else going on here, not a typical asthma picture. Sick boy.
3.) Agree.
4.) Agree.
Hope that helps a bit. What are you studying?