Yes he did go 'flat' (good way to describe it!) outdoors, and indoors lights were definitely his thing for a long time.
I think that I felt he was fully seeing from about 18m old, he was definitely sociable and smiley then..indescriminately so tbh, I could have left him with anyone as he never had separation anxiety, was happy to go to anyone (and did!)
I can't remember when he mastered eye contact..he is autistic, but it is a myth that autistic people can't maintain eye contact... my whole career has been with you children with severe autism and many of them are the exact opposite...intense eye contact! Charlie's visual skills developed gradually and it was a while before it dawned on me 'hey it's ok now'
Yes he was speech delayed..both understanding and speech production . He also had poor muscle tone which affected his ability to speak. He was non verbal at 3, started special school at 3.5, and at some point started talking but was unintelligible to anyone outside the family until he was about 9.
However once he started he didn't stop and hasn't shut up since :) He is very articulate now.
He also had glue ear which did't help, as his hearing was poor, but two lots of grommets later that self resolved.
Basically at 6 months of age he was a floppy blob. By 12m he was smiling more but not sitting very well. He was 2.5 walking, 3-4 for speech to emerge. He was assumed to have severe learning disability but once he could talk we realised he had understood much more than we thought. He IS different. He is autistic and his brain works in a different way and he will always need some support, but he has outstripped everyone's expectations! He has a job which is rare for someone from special school. He can walk our dog, he has a good friend from school and he can hold a great conversation about his interests...he's repetitive mind!
At 1 his future looked pretty bleak. Now I wish I could go back and tell myself it would be ok. My worst fear was autism, and yep autistic. But gentle and kind and loving if a bit bewildered by the world and how people are.
I might add that on balance, he has given me far less worry than his neurotypical siblings 
and they adore him and will support him when I'm too old and decrepit!
It's one of those watch and wait deals unfortunately. One thing I would say is start fighting for every bit of support NOW. It may be you don't need it at all, and he will simply outgrow his DMV and no other issues, but if there are delays, you want to be on a SLT list, an OT list, etc etc etc!!!