>I think the angle isn't very natural and will look into improving that.
Something like -30 degrees should be OK.
>The grips are from old rubber that started to become gross and sticky. I would like to get them replaced with hard plastic. Does them being soft have any benefits? I prefer hard surfaces and will wear biking gloves anyway because I like having excuses to wear gloves.
Soft ones like silicone/rubber/foam will absorb vibrations and provide more comfort, pretty much like a mattress. Gloves are still an excellent idea, get full finger ones with some padding in the palm.
>Won't wearing a helmet make it more likely that I become a cripple? If I get run over by a car I prefer having my brain destroyed and die instead of having my spine destroyed but surviving. Imagine waking up in hospital paralyzed and not being able to kys.
Cars are not your only worry, you can simply crash while riding. So get a helmet, and don't be a cheap bastard, you don't need something super fancy but don't buy the cheapest one either. MIPS is a nice plus if you want to shell out some extra moneis.