NOAA says Cape Suckling to Gore Point is E30 knots and 9' seas for Saturday, so might be a little uncomfortable taking a glacier tour out of Seward except the short one to Bear Glacier and on an E30 that could be a little rolly. If you want to see Galciers and a whale or two, then Whittier might be a better choice. Guessing both will be rainy.
As for the railroad, you can rent a car a heck of a lot cheaper if there is more than one of you, and except from Portage to Moose Pass the rail parallels the road. By renting a car, you can adjust your schedule to cram in as much as possible - timing to fish in Sevard or catch a cruise may be a little difficult if traveling by train. You can also stop and see sheep along Turnagain Arm, the spawning red salmon in Ptarmigan Creek, etc. Don't try and catch the reds, but if you have a fly rod and a egg imitation you might catch a dolly or rainbow there.
If flyfishing is of interest, you might also want to consider a rafttrip down upper Kenai river starting in Cooper Landing (off Seward Highway towards Kenai maybe 10-15 miles). Or maybe try for a silver at Bird Creek along Turnagain Arm (try a Vibrax spinner and watch the mud).
Whenever anyone I know comes to town I always recommend they spend a couple hours at our museum. I think they have done an excellent job with it.
Enjoy yourself, and come back when you have more time.