If you got an electric bike, that could help with the sweat. The breeze with the extra speed and the reduction in effort really reduce the amount of sweat dramatically. Or just bring a change of clothes and maybe a towel if that is tolerable. For the rain, a bike poncho works pretty well, especially if you pair it with rubber boots (maybe have a change of shoes ready). For the cold, gloves or bar mitts work pretty well. For the chain grease, you can get a full chain guard to house the entire chain if you want, or just tuck your pants into long socks, or get a pant clip. Given how much maintenance people often have to do on cars, a little care to have the right gear for biking is often easily well worth the effort and cost.