We would also be very interested to know which monitors can be attached and which resolutions are possible at which frame rates. 4k@30Hz is supposed to be possible according to the data sheet, but whether the built-in Thunderbolt3/USB-C type is also capable of that? Unfortunately, Lenovo support is incapable of answering this question! It didn't work with an Apple Thunderbolt display and original adapter, despite previous confirmation from Lenovo!
Dear Digitec-Team, would it be possible to test this Yoga 730 13" i5 e.g. on a LG UWQHD 34" (3440x1440) and see if 60fps are achieved and the CPU/GPU is still able to calculate? Thank you very much!

Yes, it has a real keyboard.
Regarding connections: find out which connection is needed for your external screen and check in the details if it is available on the unit.