Glad to hear you are finally bonding with the OM-D.
For faster focus, I'd recommend O45 and PL25. P20 is a great one-lens kit that's very versatile, but it's not as fast or silent focus as O45 or PL25. If you want one small prime to couple with the zoom lens you've got P20 is great though.
Another way to look at this is to ask "what CAN'T I do with the 12-50?" and my take would be fast portrait as the F # goes up on the tele side. For that, I'd recommend O45 which gives you type of picture you can't really get with the kit zoom. That said, PL25 looks awesome on OM-D, and I really loved the rendering that lens gave me (Ask Keith). If you don't mind the size of PL25, it is a perfect standard prime, and again, I think you won't get the image that PL25 would give you with the kit zoom.
That said, you just can't go wrong with the small P20 though. Amazon have them in stock right now for regular price, not beefed up ebay price.
O17 will shine with tiny camera body like E-PM1 IMHO. With larger, more full-featured body like OM-D, the size difference between P20 and O17 is very small.
For small wide, consider P14. It's TINY (smaller than O17) and light, and IQ is very good especially for the size and the going price (see ebay for "from kit" new lenses going $160 ish).