Heh. Kilburn may not be the most upscale neighbourhood in London, but in terms of safety its totally fine. Particularly down the southern end of the High Road which is really closer to Maida Vale. Kilburn High Road is always busy, even after midnight, which adds to your sense of security.

As for good pubs in the area, the Black Lion (further up Kilburn High Road) and the Priory Tavern (nearby on Belsize Road) are worth checking out, as is the Clifton (on Clifton Hill).

Transport connections: the Bakerloo line isn't London's fastest tube line, but it does take you directly to Paddington, Oxford Circus, etc. For other destinations you can use Kilburn High Road station (very close to the Marriott) which gets you to Euston in 11 minutes from which you can connect to the Northern and Victoria. Or, change at Baker Street for the Jubilee line (an easy cross-platform connection).