Cute houses! I would use my walking foot to SITD ( stitch in the ditch)on the sashing first. I like to SITD first as FMQ can distort straight lines. Try your marking tools on scraps first to make sure you can remove them safely.
As for marking first and quilting, it depends on what designs you are going to quilt. If you are going to do straight lines or gentle curves then a walking or straight stitching foot with the feed dogs up will be fine. I usually quilt along painters tape for straight lines. If you plan on doing details like shingles on the roof, paving stones on the walkways etc. then those are easier done with FMQ ( free motion quilting) and a hopping or darning foot and the feed dogs lowered.