Yeah. The first story states straight out that Watson is "as brown as a nut and as thin as a lath" in the beginning; later he's described as sturdy and well built, and he walks his rounds as a doctor and does some pretty damn athletic and acrobatic stuff while helping Holmes out, so he can't have been fat. That one's a Hollywood screw-up.

I can see an argument for bisexuality and victorian repression, and I can also see Watson being totally straight (Holmes I see as just plain not interested, except possibly towards exceptional individuals. He's got better things to do with his time and brain than fuss over women. Or men.). There's definitely a deep connection and affection there. Whether that translates into slashiness is rather up to the individual reader, I suppose.

Er, yeah. I've read everything canonical a ridiculous amount of times.