🚀 go-pugleaf

I have some questions that might be obvious for people with some linux
experience but I'm new to this so forgive the stupid newbie questions.

I would like to have a setup with two different distributions of linux
that could be chosen at boot time, probably RH and Slackware.
The questions I have are:

1)How do I work out the problem of having two "root" partitions with two
boot images?
In the RedHat install it will only allow you to select one root
filesystem and only one can be bootable. It seems like there must be
some way around this though.

2)How much do the two different distributions have to be separated? In
other words, should there be a different /, /usr, /usr/local, etc. for
each one?  I know the install/config files are going to be setup
differently but it seems like there should be at least some common
ground.

3)I already have WinNT4.0 and Win98 filling up my primary hard drive,
and so I was going to put linux on the second drive. Could this cause
any potential complications?

Thanks for the help in advance,

Jason