What does it mean when 12th Lord (Mercury) in 7th for a Libra Ascendant? (apart from these 2 predictions: expenses on/for spouse and spouse may be from far away)

Male 28 may 1991 16:06 Ahmedabad Gujarat Which gemstone I can wear for my career and wealth?

Should marriage date chart planets also be aligned with birth chart planets? is this thoery valid? eg.. if marriage date chart has jupiter sun conjunction in pisces, and if birth chart lagna is applied, say leo ascendant then this combination occurs ...