Somebuddy, I remember now, you posted previously about Google cycling maps, yes? I'm about 20 miles to the south of Lexington in Westwood.
Hopefully you enjoyed your tour -sorry about the storm! In the past I've also included my tent and sleeping bag (in their respective bags) in the bike box with no problems. I also have taped my pannier bags together to make one bag as well, which worked well.
I think much may depend on which airline you use -fwiw, I've always found BA accommodating. My advice is to always print out the rules and regulations from the web site so you can *politely* back up your point if they question anything at the check in. Have a credit card ready or ask your sister or whomever is with you if they can wait until you check in your bike for worst case scenarios.
Concerning packing the bike yourself (assuming you are reasonably confident), I'd do it and save the money. Why?
-in my experience, if it's your bike, you'll pack it the best
-you'll save some money, yippee!
-even if you pay the bike shop to do it, and it gets damaged in transit, there's not much you can do -usually you'll have to deal with the airline -anyway, even if you might think they packed it improperly, you'll be an Atlantic ocean away...
Take your time packing it -I usually put the pedals on facing inwards (assuming you secure it so they can't scratch the tubes.) I'd definitely recommend using a couple of pieces of wood/strong plastic that can protect your fork and rear dropouts too. I usually take my rear derailleur off too (still attached to cable), wrap it, and tape it to the inside of my rear triangle -though I could see some people saying this might be a bit of overkill. Twist the handlebars sideways and assuming your Tricross has STIs, remove them and tape them to the inside of the bars or front triangle (expensive to replace) so they are well protected. Lower the saddle all the way. I didn't used to protect the crank, but now I do by using a large piece of hard foam the chainring can rest in. More than likely what I've posted is overkill but given the ease of removal and time penalty to put everything back and the cost involved if you break something, I think it's worth doing. Oh, yeah, make sure you can get that box in the car beforehand if your sister is driving you to Logan.
It's nice to leave home, it's nice to get back

This weekend is looking a bit rainy at the moment too around here, sadly.
To answer Nigeyy as to where I am. This is my first tour. I flew from Edinburgh to Boston, Massachusettes via London.
My sister lives 12 miles out of Boston, in Lexington. I bought a bike in a local bike store. It was a toss up between
The surly long haul trucker with disk brakes or I know it's not really a tourer but the specialized tricross sport!
I previously owned a tricross 2010 model and wasn't sure if I would really get into touring and thought if I bought the surly it might spend a lot of time in the shed. So I got the tricross sport.
I cycled from Lexington into Boston. Caught a train to Manchester Ma and cycled north up the east coast heading for
Bar Harbor. I got within 40 miles when the tail end of a tropical storm hit. I decided not to continue, and cycled back to a town where I put the bike on a bus. Wish I had done more, but hey! I have been over here for 5 1/2 weeks now and am keen to get back home. Maybe I'll continue to tour ........