Sorry to say this pee, but you're beginning to sound like the Lappeenranta Marketing Director! I note your point about Rovaniemi and the 'Santaland' trade, but this is highly seasonal (concentrated into a single month with many clients travelling on a day-excursion basis). These trips are also very expensive by European travel standards and tend to be a 'once-in-a-lifetime' gift from Grandparents to their Grandchildren etc. They primarily travel to see the kids' faces as they "meet Santa"; the natural attractions of Northern Finland are just a pleasant bonus to them. And I would have to point out that Rovaniemi, well-known as it is, is not a high volume destination on a year-round basis. Lappeenranta, and it's doubtless very attractive environs, is simply unknown internationally and would require massive marketing efforts to fill regular Boeing 737 sized aircraft even at very low fares. You asked me if I think the region's shores are empty ... the answer is I don't know, I have no idea. But that is the very heart of the problem! If we who work within this wonderful aviation industry are not well acquainted with the attractions of your region, do you suppose that the general public will be? Before customers will aspire to visit a destination, they must first appreciate fully what it has to offer.
With regard to Russia, £30 per person visa charge is a significant disincentive for short-break travellers on a budget. Form-filling, then releasing one's passport for even a week (if clients actually realise how long the process will take anyway) represents a significant hassle for the type of impulse clients which locos need to attract. Most clients will tolerate this in return for six weeks in Australia, but not for three days in St Petersburg.
I respect and admire your desire to promote tourism to your region, and I don't doubt that it offers abundant natural beauty as you suggest. But airlines must seek profit-centres, not remote low-volume destinations which appeal to a niche market only. I must stand by my assertion that profit would be hard to come by for a UK loco serving Lapeenranta, and potentially more profitable destination airports will be pitching hard to attract their business.