Premiere Pro CS3

Hi I'm a FCP user. Recently our office upgraded to CS3 and I got the Production Suite (mainly for AE8+Encore). I had read some good reviews and decided to play around with Premiere to see if it could speed up workflow. I have a few questions (or they may be bugs) that I can't seem to find the answers to and was wondering if anyone could answer:

1) About 50% of the time I hit play on a sequence nothing happens. The play button is activated, but the time code and picture don't move. The computer isn't locked up, as I can change tools, scrub, etc. The only way I can get it to work is to minimize Premiere and come back a minute later. Is this a bug? It makes me hesitant to cut with it if I have clients in the room.

2) In FCP you can hold down shift and move a clip up/down a video layer without it slipping on the timline. Is there an equivilant quick key in Premierebesides using the snap function?

3) Is there a way to create different sequences using different codecs in the same project? (ie 1 NTSC DV sequence & 1 720p HD sequence)

I'm sure some of these are just due to my inexperience with the program, but I'd appreciate any help. Thanks!

Running:
PowerMac 2.66 Dual Core Intel
2 GB RAM - OSX 10.4.10