Kayaking the Bohuslän coastline is excellent. Easy access and beautiful. Most parts are easily travelled. Some parts are more exposed to hard winds and seas. The tide is very limited although storms may have some effect on water level.
I would suggest using "land" maps rather then nautical charts. The nautical charts do not include land features that are important for choosing camp grounds. Smooth, flat rock or even sand or grass can be identified on land maps.
Map info:
http://www.lantmateriet.se/en/Maps-and-geographic-information/Maps/Terrangkartan/Tryckt-Terrangkarta-/
Pitching tents on granite. I suggest, if you have the option, to use a self-supporting tent. A dome or something like that. A tunnel-type tent also works but you would have to use rocks and other stuff to support. Thick mattress/ground cover is a good idea. Sleeping on rock is hard.
Ticks are not a big risk factor. There are some ticks and incidence of lyme disease and TBE (tick-borne encephalitis) is incresaing although quite uncommong. You may consider vaccination to protect from TBE.
VHF is not really required in my mind. A cell phone will work excellent. If you have a VHF you can bring it as a backup I guess.
Swedish national radio provides weather forecasts several times daily. Also for coastal weather. This is only swedish.
SMHI provides weather forecasts in English online.
SMHI weather in English
Cellphone coverage is excellent. Shouldnt be a problem.
Remember to fill up on freshwater when you can. You will find good water in any harbour or town but almost none in the uninhibited parts of the archipelago. There are toilets and garbage disposal at the most popular spots in the archipelago. Please use them.
Excellent kayaking outfitters:
http://www.kajakcenter.com/en/
http://nautopp.se/
Good luck!
Pelle
