dave, personally i only feel confident riding in pants. no matter how hot it gets outside, i'm not wearing shorts nor flip flops.
gloves, boots, jacket, pants, brain bucket. sharing the road with 'cagers' i wouldn't dream of wearing anything less.
but maybe thats just because i'm starting out. and with more 'flight hours' confidence grows and makes comfort a higher priority...
I have been riding since 1975 and always wear proper personal protective equipment - leathers, (separate waterproofs), boots, gloves and helmet every time. Riders who wear anything less than this are taking risks that I am not prepared to. I only get one life, I hope to live it to the max.
FWIW, leathers are preferable outside the urban environment (i.e. over 40 mph) as they do not have a warp and weft, so do not snag on road chippings in the event of a tumble. Textile clothing snags on road chippings, this tends to make the body flail about and limbs get broken. If you must wear textiles, go for a product with the finest threads, as they provide a smoother surface and so reduce the snagging risk outlined above.