1) Not sure about regular Windows 10, but you have two options in Windows 10 Pro.
a) You can specify your network connection as "metered", and Windows won't download updates while connected to a metered connection.
b) You can "defer" updates in Windows 10 Pro. http://www.computerworld.com/article...ws-10-pro.html

2) Isn't this true of any version of Windows?
I'm running Windows 7 Pro at work, and I can't update unless I want to spend $2500 for a new plotter that works with Windows 10.
Does anyone seriously think that microsoft will come out with an update that makes hardware obsolete? Keep in mind that the vast majority of Windows users run pretty low spec machines.
I have a few 10 year old software programs that work fine in Windows 10. If you want to run programs older than that, than you may want to hang on to your copy of XP.