It really depends on what you’re trying to do with the degree to begin with and what sorts of jobs you’re after.
If you’re intending simply on studying the BSci and then going straight into job hunting with the idea of getting a related job, then I would say that the prospects are close to the same as any other general degree that doesn’t have placement or accreditation attached. As for length of time, I would say that most grads take some time to get a job after finishing their degree and I often find people underestimate how long it takes to get a job.
In the biomed vs. science debate of job prospects, I would probably say they’re about the same? In the biological/health sector, I’ve not really seen a biomed grad be picked over a science grad with a relevant-ish major, nor have I seen many job ads that specifically requested someone with a biomed degree (read: quite rare), so there’s not really a lot of segregation or outright prejudice against either degree in that regard. I would dare say that biomed is also seen as a stepping stone for grad programs just as much as science is, in all honesty.
What you also need to understand is that a degree is simply more of a tick box in related jobs and most employers will care more about what you’ve done along with that degree than the degree itself when choosing who they want to hire, because most of your competitors will likely be other grads who did similar degrees anyway, if the job requires a degree to begin with. The skills and experience count more than the knowledge, so if anything was to separate job prospects between people, it’s that, rather than their chosen degree.
For biochem, I think either science (majoring in biochem) or biomed would work there. I did my BSci and subsequent Honours in genetics, which is pretty much the other side of biochem (just that biochem cares more about processes/ pathways than genetics does) and got a job within 6 months of finishing my thesis. The big reason that I got my current, related job? Not even my degree, it was actually because of things I chose to do in my spare time and my part time job in the health industry.