As far as the shift points, I would check the TV cable first. Generally, you can pull the clip on the adjuster and just push the cable out and let it return, and lock the clip again. From that point it is kind of a preference thing. I like them set pretty tight, which will to some extent, make it do what your describing. Try loosening the cable one or two notches and try it that way.
Cold weather especially will make the shifts sluggish on its own. If the fluid level is even a little low, sometimes it will be drawing some air in as the fluid is slow to get back to the pan. This can affect shifting as well as clutch engagement.
The shudder your describing sounds more like a torque conv. slipping. Or OD clutch slipping. What ATF are you using. The ATF +3 or whatever supercedes that(+4) is the specified fluid. If your running anything else, you can get some weird shudder problems that you wouldn't otherwise get. I don't remember when they started, but alot of the trans have staged TCC engagement where the clutch is applied using a duty cycled solenoid that first applies partial pressure and later applies full pressure to the TCC. It makes the transition to TC lockup less noticeable. Thank those who want a buttery smooth shift.
Lastly, a 97 FSM should get you pretty close. Some wire colors or options change from year to year, but anything 96-98 should be similar. Even in th correct manual, sometimes info like wire colors is wrong. Or compression specs. I had to go rounds w/ a factory engineer once when the spec I read out of the manual was supposedly wrong. In the end they confirmed that it was right, but in the mean time it was real helpful of them to give me inaccurate info.