Use a wading staff for additional support. I like the Simms Rivertek wading sandals, might give them a try. As far as indicators go, I like and highly endorse the "Thingamabobber" available at most fly shops. Available in four sizes and various colors - even glow-in-the-dark - I like the white and use the small size glow-in-the-dark on spooky water during the day due to its smokey/dun color.
I don't use mosquito repellant.
Good luck, but if nothing else, make sure you use the wading staff for extra support while you wade.
Kelly.
Tight Lines,
Kelly.
"There will be days when the fishing is better than one's most optimistic forecast, others when it is far worse. Either is a gain over just staying home."
Roderick Haig-Brown, "Fisherman's Spring"