I think that optimal variant would be to have starting vessel and its equipment depend on initial career choice, to have equipment be more important part of ship's value than the actual hull and to have various kinds of equipment primarily suited for particular career paths and not necessarily useful for some others (for example tuning Panther's engines for speed/acceleration with won't really help much - it will still be a flying brick, but it will waste money, cargo space and possibly fuel efficiency).
The idea is that, in addition to a handful of credits, for example a wanna-be courier would get small hull with some expensive gear to improve speed and evasiveness, while a wanna-be trader would get largish, but mostly empty hull with just basic drive, autopilot and some extra initial funds to start some reasonable trading career, but both starting setup will have equal credit value to prevent choosing different setup than desired career and trading it in for more money.
It would be nice if ED didn't force players to pursue uninteresting career in order to afford one that would suit them better.
Of course, there would be nothing, but need for cash to prevent switching later on.