9 times out of 10 I get stuck on checking for updates screen right after the first splash screen.

The only solution I found is disabling my internet connections and start the game offline, then enable back the connections, go inside the options and enable all the online features.
Is there a better solution around?

Are you using Google Map Enhancement Addon? If so, check your hosts file for two entries it adds:

127.0.0.1 kh.ssl.ak.tiles.virtualearth.net

127.0.0.1 khstorelive.azureedge.net

Delete them and save hosts. Had a similar issue to you and that fixed it.

Of course,  if you are not using it then you can ignore the aboive.

Rename your Community folder to Community.old - launch the sim as a vanilla state see what happens.  If it loads then you know its addon related before you go down any other route.