95 is not "flash" readable like 93 ..and '94 may be maybe not. Flashing the codes needs contats A and B in the computer plug....
There are codes readers that are "OBD1" compatible...they are more expensive.
Fans: when you use the DEF position, as well as DEF/HT mix, A/C is trigged on at same time and then fans come ON. This is because a/c acts at same time as dehumidifier and this helps clearing the fog. I do not like that A/C be energized without my own consentment...and in my other cars, where this cross action is from a mechanical switch, I have disconnected it. With this one, is comes from the computer....so have to live with it.
Yes..temp sensors are positioned in the worst place they could find. Just below throttle body is the 2-wire computer temp sensor...the one that should enable starting the fans when it gets hot. THere is another 1-wire sensor farther back just for the indicator....So....while these are generally sturdy and correctly matched, there is no absolute garantee they tell same temperature.
About transmission shifting: downshifting when pressing hard is quite normal....this engine does not rev easily over 4500 rpm...so between 2nd and 4TCC, there are several gears: first, TCC comes off as it stays in 4tn gear, then will shift to 3rd....may be it will shift to 2nd is slow enough....I'm not sure '95 has a throttle cable to the transmssion..but there is a vacuum modulator...a leak in the vacuum feed to modulator can make it downshift much easily as loss of vacuum is like depressing the throttle to the floor...so if it really seems to downshift in an abusive manner, check for that...and eventually, for the modulator itself.