Small shops can be challenging.
I have been thinking of selling the big mill for something smaller.
Before you get too serious about that, look at the foot print of a smaller mill and compare to your current mill. Since I doubt you would be looking at anything smaller than my Clausing I can tell you how much space that takes up. Leaving room for full travel but not including the space for me standing in front of it, I have dedicated an area 4 feet deep, by 4 feet 8 " wide. Just a guess but if you went for something the size of Bob's Millrite, probably add another foot in each direction? How much area would you actually gain going to a smaller mill?
Height and getting into the shop were the major concerns that led me to a smaller mill (my wife made rare use of her veto power at the suggestion of cutting a hole in the kitchen floor above the shop).
Also keep in mind the table and travel tends to take up the largest area, but it moves so creative placement could provide some work area to either side of the mill, just have to move the table to the opposite end of travel. Also room below the table which can be used for storage, just ensure what ever goes there is chip tolerant. Looking at the photos from February it looks like you have a pretty good sized hole between the vertical mill and surface grinder, and behind the mill table. Could be a home for your drill press, horizontal mill or if on wheels a parking area for your new bandsaw. Just have to move the table to the right when you want access to that space. Another option would be a shop vac cubby, I know my shop vac is always under foot, as they take up so much room when not being used. Machine Tetris isn't limited to putting things on castors.
I have my horizontal mill and vertical mill quite close together. Their table travel actually overlaps (good thing I only use one at a time) and if I need to get behind the machines I have to move at least one of the tables to their opposite extreme, and both if I actually need some room to work between them. I'm working on a low rolling cart to sit between them for storing the mill tooling in what is otherwise wasted space below the tables.
Similarly I built a low shelving unit for metal stock which lives behind the Clausing. I needed to leave room for the head to travel backwards but that left an area about 14" deep, 4 1/2 feet high and 4 feet wide that would have just been wasted space. The shelf is 4 feet wide x 4 feet tall and 12" deep so actually provides a decent storage area.
Indeed, the more grinding I do, the more I am aware of the fire hazard from sparks. I'm considering making a 'blast shield' using a couple of pieces of 24" x 18" plywood joined by a piano hinge. Stand it up in a 'V' so that it catches the grinding debris.
I weld in the yard outside of my shop. I have to rake and weed wack often, and wet down the area around where I'm working to help contain any fires. Welding I've started a few small fires in the short grass but slow moving and easily stamped out. The one slightly scary fire I started was cutting expanded metal with an angle grinder, that was like using a flame thrower. I always have the garden hose charged and ready, as well as have an ABC dry chem extinguisher, a pressurized water extinguisher and a shovel handy. I know some of the local firefighters and have no desire to give them any work.