virtualbox.org

I have a few questions re: Virtual Box that I trust someone in this forum can help me with.
I currently run a dual-boot system of Ubuntu/Win 7. I only use Windows on occasion spending most of my time
running Linux (95/5%). Every time I do want to run Windows, of course, I have to do a restart and log into Windows wait for
it to boot up and so forth. It occurred to me that it might be easier to run Windows 7 in VirtualBox on the Linux side instead.

Questions:

1. Does this make sense ? ( is it practical) ?
2. Do I still have to be concerned about malware / virsuses, etc. while running Windows in VB ?
3. Can I download Windows specific programs and run them in Windows VB ?
4. How many Gb should I allow for a Win 7 installation in VB ?

I've used Wine which is OK for some applications and I've tried Cross Over but wasn't overly impressed.

Any help / advice would be appreciated.

Regards,
Bruce

Your questions are very basic, answered in the user manual or FAQs; or in the case of malware Q, asked and answered on these forums many times. A bit of reading / googling will do you the world of good (use site:forums.virtualbox.org to restrict the search). For us the prospect of retreading all of that territory is not very appealing.