Q: Engine temp gauge rises quickly

I know this engine has had issues and I have been getting coolant in my oil since around 125000 mi. I didn't want to spend the money on a new head or engine so I have been running synthetic oil and changing around every 5000 mi. I added some bars leak to the radiator, that seems to have stopped the coolant to my oil. The temperature gauge always ran around between a 1/4 - 1/2 mark. After I put the bars leak in its been running more towards the 1/2 mark but it has been a hot summer here. The water pump failed and I replaced it with a aftermarket pump. It failed again as my daughter was driving down the highway and she said the engine got hot on her but I don't think she drove it very far that way. I replaced the pump with a new pump not aftermarket. Gauge would run around 1/2 - 3/4 but would get there fast. I then replaced the viscous fan seemed to help but still running high. I replaced the thermostat. It will run to 3/4 but not in red. Could it still be a bad thermostat?

My car has 193000 miles.
My car has an automatic transmission.