You should know that State St (79) will be closed between Stewart and Quarry for construction; there's also no shoulder on 34 because of construction. In any case a much better route from where you are staying into town would be the back way via Cornell campus:
Best Western to Downtown via Cornell

As for getting up to Lansing, again here's a much better route, without having to go downtown and avoiding the ripped up shoulder on 34 down by the lake:
Best Western to Van Ostrand Rd via Cornell & Cayuga Heights Rd

Also you should know that Creek Rd headed into Locke is torn up, it's been milled for repaving and I don't think they're done yet. Also if you can avoid Peruville Rd you should, the shoulder is pretty bad in places and there's a fair amount of traffic.

On this bit:
Right on Peruville, descend down to junction of 38 and 34B. You have two options: straight ahead big hill climb
Don't go straight. Peruville Rd east of 38 for a few miles has no shoulder at all, the road is not in very good shape, it's an uphill climb, and there's fair amount of traffic. You can turn right here on 38 and ride to Fall Creek Road in Freeville, turn right, and follow Rt 366 to Upper Creek Rd, right, then keep following Lower Creek Rd (there's a left turn to stay on it), crossing Rt 13 as mentioned above, straight onto Hanshaw, left onto Freese. Going straight up Mt Pleasant is a pretty big set of climbs, if you love climbs go for it, otherwise you may want to avoid that and turn right onto 366, right onto Forest Home Rd, which is a beautiful forested quiet road right along the creek, then back in, here's the whole route suggestion based on RollCNY's route:
Best Western to North Lansing School Rd, back in along Fall Creek, 39 miles

Here's another suggestion headed out east from where you're staying:
Best Western out to West Creek Rd and back
Ellis Hollow Creek Rd is a nice forested road, it's got a bunch of rollers, then at Slaterville where there's a store and ice cream place, you head east on 79, there's a nice shoulder, traffic usually not bad, ride about 6 miles then turn onto West Creek Rd, head into Speedsville, a small store there, then onto Old 76 Rd -- it's a bit trick here, be sure to head straight at the stop sign (park to your left), old 76 also turns left, but you want to continue straight. You should check to see if there's construction on Old 76 though, I think they plan to repave this summer. Then Central Chapel to Burn, nice downhill into Brooktondale where there's a little market, along Brooktondale road, up to 79 and back in, about 35 miles.

Anyway if you like climbing I've got some excellent hill climbing rides too, and if you want longer rides checking out the lakes let me know (for example riding up and around Owasco Lake is about 70 miles total from Ithaca) these are the roads I ride all year round, I know them real well, and they're beautiful!