I`ve just run the sim for 15 minutes without any in game crashes,nothing very ambious mind you just swaning around the sky in my spit.As mentioned before the only issue is with the english text error,that seems more likely to happen if the ground object density and particle filter is set to full,also running the sim for extended periods eg.15 mins in this case but as I have only just noticed that perhaps it`s a red herring and was only evident on keyboard command Alt X.
As for Win 10 the install only allows you to overwrite an existing copy of Win 7,as I have a spare blank HD on my PC this was no problem.I have not installed any other software on the OS with the exception of the graphice driver Nvidia 347.52 and DX9 At the moment Win 10 looks to be a winner [Hopefully].I would be pleased to help with any other info you may require.