Jason...rare that a leaky hose would cause a slow start condition. If you do smell gas and suspect a decrepit hose, by all means get it checked if you don't have much experience working on these engines. Every once in a while...every few months an old BMW goes up in smoke due to an engine fire...very common....do to all the heat aged 8mm high pressure fuel line used on virtually all old BMW's. If you suspect a leaky hose, I would change all of them...I did so last winter on my '90 735iL. As to your slow start...provided your electrical system is up to snuff...likely a fuel rail bleed down issue from either a failing check valve internal to the fuel pump which is resolvable by adding an in-line check valve...BMW sells these and they are inexpensive...or an ailing fuel pump itself. You need to assess your in-line fuel pressure to see if your pump is providing adequate pressure versus simply losing pressure after the engine is shut down.
HTH,
George