1) Yeah, you can get a chance to meet people after the appropriate chapter. The chapter number is more of a "don't expect them before this".
2) Not finding Steve in ch4 is part of the story.
Check the nightstands, if using a mouse or touch you might have to click on the lamps
I added a walkthrough to the guide just in case:
https://docs.google.com/spreadsheets/d/1nlO2owvibS5tvHbFyK83FGQc0PcGN16cWm7aq3Q4...
If you are using touch or mouse you might have to click on the lamps on the night stand rather the night stand itself.
Just in case I added a walkthrough to the game guide:
https://docs.google.com/spreadsheets/d/1nlO2owvibS5tvHbFyK83FGQc0PcGN16cWm7aq3Q4...