Project path question

I have some questions concerning paths in TeamCity

let's imagine that we have an svn repo svn://domain/repo with branches/tags/trunk and many different projects in trunk, i.e.
svn://domain/repo/trunk/proj1
svn://domain/repo/trunk/proj2
...
svn://domain/repo/trunk/proj100

I want to make build only for some projects on build server (e.g. proj2 and proj4) which have similar configuration - build.xml as ant runner and /out/bin as output artifacts folder, and I also want to have esy extensibility - i.e. ability to add new projects via cloning rather that configuring from scratch.

So my questions are:
1) How to checkout only some folders and not whole repo? At the moment I have svn://domain/repo as shared repo + 2 checkout rules for every project (-:. and +:trunk/projX), but maybe there are better way to do this? Unfortunately whole SVN(expecially with branches) is too big to be checkouted.
2) How to make relative paths for project so I can use build.xml for ant runner and /out/bin for build artifacts rather than /trunk/projX/build.xml and /trunk/projX/out/bin?