Best way to add a video to presenter

Hi,

We're planning 3-4 eLearnings that will have 4-5 short video clips in them.

What would be the best way to incorporate them into presenter?

1. Best format?

• When saving will AP save them as .flv no matter which format they were originally in?
• Will AP compress them? (so it doesn't matter which resolution they had to begin with) 

2. Loading

• Does AP preloads the next slides, so a slide with a video will start preloading before it is palyed?
• Would AP preload a video that  is embbeded from an another site? (we have an internal video service that we can embbed)
• Can you give any tips regarding which option might be faster from the two previous ones?

Any other tips regarding video use, streaming etc. are most welcomed. 

Thank you!