The things that jumped out at me right away from the photos:
1. The paint at the trim edge below the table doesn't go all the way to the bench edge... It looks like they just didn't finish the trim work for it.
2. There are no cushions.
3. The benches either don't open, for use as storage, or don't open, for access to the utilities they contain (that's a lot of wasted space for such a small trailer).
4. The doors on the storage area over the bed aren't hung straight. I tried to discount this as an optical illusion, but it just didn't work - you can see the true edges at the top and bottom of the storage area, and the doors clearly aren't hung true.
5. The trim on the edges of the dinette booth is cheap, poorly applied, and ineffective (coming off/fraying at the bottom).
6. The windows aren't fully trimmed - look at the bottom corners and you can see where a square hole was cut for the window with the triangular notches at the corners of the rounded windows just blocked in but not painted or trimmed to fit in with the rest of the wall.
7. The table can't be lowered to the same height as the dinette benches so that the dinette booth can be used as a bed, another strange choice for a small trailer.
My 5 year old inexpensive entry-level trailer (is put together and/or holding up much better than that trailer.
Lots of trees, large isolated sites, no camp pad (put the trailer wherever is convenient - ala Algonquin PP, Pog Lake CG), direct water access (lake, river or stream, as appropriate), view of water, access roads that are arranged in such a way that there's very little traffic on any single road except maybe a central artery, large clean bathhouse with laundry facilities that work well, very quiet (no road noise - I want to hear the animals at night and the birds in the morning), a variety of hiking trails with varying distances from hour-long easy hikes, to day hikes, to overnight hikes, to multiple overnight hikes, and the same for kayaking and kayak camping, some trails hilly/mountainous (not too extreme - very close to the ideal is the hiking Acadia NP in Maine and the kayaking at Lake Superior PP in Ontario).
Don't care about electric, water, pavement, or other amenities. If they're there I use them, but where I camp they're usually not there.
Except for the oven (for obvious reasons) we cook entirely outside. We're originally tent campers though, and still do back-country backpacking and kayaking trips. We're just more comfortable cooking outside when camping.
We use a re-usable pour over cone filter for coffee. Small, lightweight (we also use it when backpacking), and makes a GREAT cup of coffee.
BTW - if using an inverter, divide watts by 10 to get a rough estimate of amperage. 1000W will pull close to 100 amps. Also, if you have a group 31 battery (~100 amp hours), you can draw it down to about 50%, which means it'll last for about half an hour at that rate with no other load. There are lots of other small loads though (refrigerator control circuit and propane solenoid, lights, water heater control circuit, igniter and solenoid, and more ...). Another big draw on the battery is the furnace - the blower motor draws a lot.
I do, along with the batteries. I suspect it depends on the trailer though - for lightweight trailers these are a more significant contribution to the tongue weight than they would be, as a percentage, on heavy trailers.
Last year one of my OEM tires (dated January '06) developed a slow leak from long thin cracks in the middle of the sidewall that ran part way around the tire. I swapped that one with the spare to finish out the year, and this spring replaced all 5 tires. I noticed before doing so that another had developed similar leaks over the winter. These tires had about 30k miles on them and the tread might have been good for another 10k.
They do go bad just from age, but it takes a while. The replaced tires, as of this January, were 7 years old with 5 years on the road (and probably should have been replaced when 6 years old).
Just FYI: If you do have a tire fail, the other tire on that side will be over-stressed from having to carry all of the load and should also be replaced.
I've seen other people do exactly as pianotuna does -- blow lines, get pink stuff through all faucets and toilet, then blow the lines again with compressed air. Nice thing with this method is that any water is well mixed with antifreeze, and that de-winterization is a lot easier, with less pink stuff to add a foul taste.
I've done this for two winters now, and it works really nicely. I end up using less of the pink stuff, and de-winterizing takes a lot less water and time.
I'd say a 3-bunk HTT would be the rough equivalent of having 5 kids in mine (we have 3)... It'd really be tight. Really tight. Definitely try it before you buy. IMO, a 3-bed hybrid plus a tent would probably work better. If the tent works well, you could actually get away with a smaller TT or HTT and larger tent.
What would work really nicely would be if the kids slept in tents, leaving the trailer for the adults. :)
Cruise won't hurt anything in and of itself.
It CAN cause your vehicle to shift more than desirable in hills - for instance, it can't see when you've almost reached the top and might downshift when it's not really needed. If it does that, turn it off. If it doesn't, leave it on. Some experience will help you know the conditions in which you'll want to turn it off.
97 miles really isn't all that high. Even if it was being used for personal use on the part of the dealer, it wasn't much. (If a person's commute is 25 miles, it was perhaps used three times.) A new car can also easily get that many miles if it's been used for test drives. Also, sometimes cars will be driven from one dealer (or dealer location) to another in order to balance inventory.
Most of the time the GPS works fine. Every now and then (construction, accidents, traffic jams) having a map is handy for finding alternate routes that others might not consider - the obvious alternate routes quickly get backed up too.
When using the GPS, I like having a dedicated GPS with on-board maps more than using my phone. We tend to go places without cell coverage, and having to load the maps in advance is a pain.
If you camp at the KOA you can take the subway from Upper St.Clair to downtown and avoid some of the traffic and parking hassles.
From Mountain Top, you could get on the subway at Fox Chapel.
No one has mentioned it yet, so I will: Parking in downtown PGH is a nightmare. Avoid it if you can.