M&M earnings on LH issued tickets are now based on money spent, so it costs significantly more to achieve SEN only flying with LH. To avoid LH P class, fly with LX P or OS P whenever possible. The fastest path to Star Alliance Gold is either TK or OZ(both for two years period). Doing that you have achieved your main goal(lounge and business class check-in), after that you can choose whatever program to credit rest of the miles. Choosing OZ and getting a US issued credit card helps you maintain the status with lower flight miles(30k per two years) and get more bonus miles. Choosing TK and flying only once during the 12 months 80k gives you two upgrades per membership year, maintaining is 40k in the first year or 60k during the membership period(two years).