Radiator puking

As for the coolant level; you got two choices;
1) Put an expansion tank on it, with a recirculating cap. Your problem will be history. Mine is from a 73 Dart. It wasn't a bolt-in, but almost. Then you can fill the rad to the top. or
2) you could do what we used to do in the old days; just run it until it stops puking and the rad will have found it's own level.

As for the stat; It serves a number of functions
1) besides the obvious of bringing the coolant temp up, quickly.
2) They say, and I don't know the truth of it, that if you take the stat out, then cooler coolant will try to short-cut it's usual path of going to the back of the block, and then returning to the front thru the heads, instead it wants to go
straight from the front cylinder to the stat-house, leaving three cylinders, on each side, to get hotter and hotter.
3) They say, and I don't know the truth of it, that without the stat, steam pockets can form, which get trapped in the heads. If your temp sensor sits in one of those pockets, it will not read accurately. The sensor only reads liquid temp.
4) They say, and I don't know the truth of it, that the stat provides a working restriction, even when it is WFO, that helps to smooth the flow of coolant thru the system.

My engine cost me too much to gamble it's life away, by running it without a stat.

As for your temp-reading;
In your system, the gauge is doing something odd that's for sure. You may have to relocate it, as it seems to be in a pocket of some kind.

As for the color of the Coolant;
Dexcool is more or less light-red ..... to Orangy-red.