BT is not that bad with reasonably cheap economy flights because they credit 100% for W class. ^ If you see you have something else on air Baltic web, ask a travel agent to make your reservation for you explicitly in W. If you connect to SK, W will give you only 25% on SK. Example - WAW-CPH-RIX in W is 150+600=750 points.

Radissons and Park Inns count to status. 300-500 basic points a night. I've only done Radissons. Also here situation has changed and not all Radisson stays are eligible for earning airline miles or points. If you book at radisson.com, rate says if it is eligible or not.

You can always do a mileage run RIX-BCN-RIX in business class would give you 7200 points for EUR 655 (LVL 460). Single flight TLL-ARN-NYC-ARN-TLL in business for less than EUR 1700 would give you silver card and business check-in immediately. You need a bit more than 8 direct return flights on BT to Germany, Belgium, UK or Ireland in W or higher to get to EuroBonus Silver.

If you have to or decide to connect, give a preference to Stockholm over Copenhagen where possible. You will then earn much more points from Stockholm for the Western Europe. Russia would be exactly the opposite.