Questions regarding gained cards through xp and upgrading.

[kisfenkin]

1) If I play a Lieutenant to my bridge, then a Commander, I have 5 xp. If I use this xp to purchase another Commander, where does he go? The rules do not state if he comes on my bridge or goes into the discard, just that, "You may spend your XP points to gain cards from Starbase." If he were to come on my bridge would he give me yet another 3 xp to spend?

2) If I upgrade a Lieutenant from my hand using Starfleet Academy to a Commander, does that Commander go to my hand? Does the upgraded Lieutenant get discarded, or trashed?

3)Alternately, if I play the Lieutenant to my bridge, gaining his xp, then upgrade him to a Commander after playing Starfleet Academy, does the new Commander go to my bridge, giving me +3 xp, for a total of +5 xp, or will the Lieutenant's xp be lost if unused before upgrading?

Thanks in advance!

[Space Elmo]

When upgrading, the old card gets trashed (ie back to the starbase pile) and the new card goes to your discard pile.
When playing a card that gives you XP, the XP exists independent of the card (it is only lost if unused at the end of your turn). So you can upgrade a Basic character and you still have the XP to spend. The newly gained card goes into your discard, however.

The main downside of the upgrade is that you lose the stats (Attack, etc) of the trashed card as you can't play the new one immediately.