1. It seems that your statues block access to cabinets.
Just using the method that is on the DF Wiki, under the 'arranged marriages' subheading:
http://dwarffortresswiki.org/index.php/DF2014:MarriageHaving the cabinets increases the value of the room and thereby the positive emotion of sleeping in a bed.
"Slept in a great bedroom" ---> "Slept in a bedroom like a personal palace"
Supposedly dwarves talk to one another while they are on adjacent tiles and have the 'no job' status. Funnily enough, the 'socialize' status is associated with performance and singing, not with dwarven interaction.
This method produced almost four marriages in two seasons, I was merely wondering about a marriage 'cap' as they stopped suddenly despite me keeping the conditions the same and allowing them to idle as much as possible.
2. It seems that you're letting them walk out of their cohabitated bedrooms, instead of locking them in. If they socialize elsewhere as well I'll have to raise an eyebrow at any marriages.
Nope, deleted my inn so that citizens hang out in their rooms with 'no job'. Dwarves are allowed to walk in and out to eat and perform tasks as it would be too fiddly to set up private food and drink stockpiles for every marriage suite.
3. Just curious, what are the two who took time to get married like? Responsibilities, personalities...
I've had about 5 separate couples end up actually getting married but I'll just focus on two individuals.
This is Etur, my broker, who pretty much since day one has been under a lot of stress lately and has never really coped with it well. She was one of the starting seven and soon formed lover status with one of the minors. At the birth of their first child, she managed to break free of her stress and has been a vital part of the fortress, despite missing a few limbs:
This is Zefon, my original expedition leader who has been in 'lover status' for about a year now with no signs of progressing on. Nothing I read in his personality suggests he has a personal aversion to marriage however.