I cannot help you with first question, but a good start for me would be contacting repo admins/maintainers (are they active? I remember there was an issue when Pali wanted to become Titan's power kernel maintainer). If it breaks important system package, it may even be a good idea to contact council. Maybe even qgil, his maemo.org's profile states he is from Nokia and happily he seems to still care about N900). Ad.2 I guess you would need to change makefiles or configs (if they are properly written, maybe it would require only a change of DEBIAN/rules file). You have to trick the linker to link to other library/other version of library, try debian packaging tutorials, I remember reading somewhere about similar situation, but don't get over excited - afaik even somewhat-official Debian multimedia repositories have conflicts wth official Debian repos due to package versions conflicts (what a mess...). You should definitely change something anyway, I know this is extras-devel, but some packages take forever to go higher (or even they never make it), many people have devel enabled just for software like psx or other game console emulators, to name a few.