1. yes, but you either use slackware provided kernel, in which case you use the .config that came with it, or you compile your own, and generate your own .config at the make menuconfig/make xconfig stage
2. if it is identical system, yes
I would recommend you do some reading around the subject first
read DaOne's post at the top of this forum, also read the info patrick provides on the slackware site, eg
ftp://ftp.slackware.com/pub/slackware/slackware-10.2
there is a lot of text files here with good information
good luck,
tobyl