For YouTube settings, I'd go to the FAQ sub-forum, found on the right-hand side of the main forum page. There are suggestions there. Note: YouTube will re-encode whatever you upload, and they change their requirements monthly, if not sooner.
Now for the Widescreen vs Standard question. I assume that you used WideScreen, when you set up your Project. Is that correct?
First thing that I would look at would be to use Interpret Footage for the Standard Clips. Do one first, and choose 16:9 in Interpret Footage. How does this look? Only you can make that call.
If the band looks too fat, then we'll move on to Plan B. Go to one of your Standard Clips, and Select it. Go to Effects, and then Edit Effects. Look for the fixed Effect>Motion. Twirl it open and then go to Scale. Increase this, until the Frame fills the width of the Frame. This will also effectively Crop the vertical. If you need to alter how that Crop is seen, go to Effect>Motion>Position, and move the Frame up, or down to suit.
You also will not likely be able to bring the Fuji Finepix video into Premiere Elements as is. You'll likely need to convert it DV-AVI before you bring it into the program, per the FAQs to the right of this forum.