Besides what you have, here are a few things that I'd recommend.
Bromo Seltzer Tower - If you got time on Saturday, I'd head over to the Bromo Seltzer Tower. It's like a 5 minute walk from the convention center. There are a bunch of art studios in the building and you can get a tour of the clock room at various times during the day.
http://www.bromoseltzertower.com/open-studio-days.cfmB&O Railroad Museum - I have a membership and love going here with the kids. There is an amazingly beautiful roundhouse here as well as a bunch of old locomotives. I'm not that big of a train guy, but I really enjoy going here. It is walkable to get here ~20 minutes.
http://www.borail.org/Maryland Zoo - It's a nice, very walkable zoo. It's nothing as huge as the National Zoo in DC, but they have some cool animals here and it's a great place. You could take the light rail there, but it's a bit of a walk from the closest station. I'd say taxi or Uber if you want to go here.
http://www.marylandzoo.org/American Visionary Art Museum - I've only been here once. It has quite the eclectic collection of art. Outside the building is cool to walk around too. It's within walking distance of the Inner Harbor.
http://www.avam.org/Walters Art Museum - I'm ashamed to admit, I've lived here for 17 years and haven't ever been, but I hear it is fantastic. Best part is that it is free to get into. So that might be fun.
http://thewalters.org/If you have a car and want to get out of the area, I totally agree with the recommendation to drive to Gettysburg, even think about stopping at Frederick, MD along the way. Annapolis is beautiful this time of year as well.
Please feel free to shoot me an email if you have any specific questions:
bosoxbrent@gmail.comGlad to have you coming out to our city and hope you enjoy yourself.
Cheers!
-Brent