I’ve been to Aland many times, to a few Islands around Jurmo. If I were to go on a cycling trip from the UK, I would fly to Helsinki and take the overnight ferry to Mariehamn. Silja Line are a little more refined, whilst Viking Line are cheaper and known as the “Love Boat”. Either will be an experience :D
I wouldnt go for a cycle tour on mainland Finland. The distances are vast between towns and there is little to see or do between. Road safety is an issue too. I’ve felt safer in Lithuania, UK, NL and Estonia than on Finnish mainland A-roads.
Aland is Swedish speaking, so the lingo should be easier. Most people speak excellent English, even the elderly. The people are friendly to tourists, the fish is fantastic and they make the best beer in Finland.
At this time of the year the bugs shouldnt be a problem. During the summer, the midges, mozzies, horseflies, ticks and mooseflies are irritating. Autumn turns to winter quickly over there, so I’d book quickly if you were going to travel this year. Mail in profile if OP/ anybody else wants to know more.