Just purchased Olympus E-PL6 coming from Sony? Tips?

I have an E-PL6, along with an E-M5, E-M1, and GH3.  The E-PL6 has a pretty limited user interface, since it does not have typical control dials.

I do wonder why you bought it, if you weren't familiar with its IQ.  It has the same sensor as the E-M5 (which I like for long exposures and low light), but only 3-axis IBIS.

It doesn't have a viewfinder, but I usually use my VF-4 on it.  That is a great viewfinder, which I use on my E-M5 or E-M1 as well when I'm shooting low.

I like it with the 14-42 EZ lens, very compact.  Or any of the smaller primes (12, 17, 25).  Jacket pocketable as long as I don't have the VF-4 attached.  With larger lenses (and that's mostly what you have now), I find its user interface too limiting to warrant using it and will go with the E-M1 (or E-M5, which is not much bigger and a lot friendlier).

The camera is HSS compatible (FP mode).  It comes with a small flash that can also be used as an RC controller for other flashes; I've used it with the Olympus FL-50R in FP mode.  As for a small HSS flash, the FL-36R is also FP and wireless.  The FL-300R is a nice small flash, BUT not FP capable.

And, if you add the flash, then one of it's features doesn't work...the flip up selfie mode on the LCD (the flash gets in the way).

I would never recommend this camera to anyone that wasn't going to use it with the 14-42 EZ or small primes, because it doesn't have a viewfinder or typical control dials.  If you're going to use bigger lenses, then might as well get a bigger (and more flexible) camera.