Although the current HDMI standard (HDMI 1.4) actually supports displays with very high resolutions, you'll face display or graphics card problems. E.g., driver and hardware (single link HDMI) of the integrated Intel HD Graphics 3000 and 4000 restrict the resolution to 1920x1200 at 60 Hz and you'll need a trick to use higher resolutions.
Yes and no. You may need to reduce the clock speed,
I am current running:
macbook pro mid 2012,
Mojave 10.14.6 (18G6020)
Intel HD Graphics 4000 1536 MB graphics, 16GB ram, SDD
LG HDR WQHD Display 52-inch(actually 34inch) at (3440 x 1440) 40hz
I don't play games, and I can watch full screen action movies.
at 45 and above the monitor spits black intermittently.
If int he UK, you can order on the internet and get it returned if it doesn't work.
I used SwitchRes