I'll give it a shot.
#1. I live out in the country. The neighbors are too far away and there's cornfields and treelines between us all anyway, so "don't go into the long grass" is something I'd have to keep in mind. Basically, the neighbors are on their own in this situation.
For small to mid sized dinosaurs I'd prefer a bolt gun in .300 win mag with iron sights and a 44 mag revolver or a Glock 20 in 10mm on backup. I wouldn't mind a Marlin Trapper in 45/70 and a Ruger Redhawk Alaskan in 454, but the 454's have been known to cause crimp jump issues because of the recoil with the short barrel, so I'd probably go with the .44 model. 500 mag would probably be out of the question in this particular situation due to recoil, unless I had access to a Big Bore Armory .500 lever.
For T-Rex, I'd honest to God prefer a Barrett in 50 bmg for noggin shots. Made here in TN and it's also our official state rifle. If I couldn't have that, I'd at least want a good rifle in 338LM with iron sights and a long barrel 500 magnum revolver because getting eaten sucks and I can't have a Tek Bow.
#2. A brand new car with a full tank of gas so I could drive away. Otherwise I'd go smaller caliber than with the dinos. Most likely the highest end AR I could get my hands on, a Ruger GP100 revolver in 357 magnum with at least a 4 inch barrel, and a Smith and Wesson m&p40. If possible, I'd like to have the semis suppressed, and leave the magnum for absolute emergencies where ammo is low, when noise is not an issue, or when I need plenty of power while in tight spaces (crawling through debris, tunnels, etc). I'd also like to have lights on both the AR and M&P40.
If I could only have one gun for all scenarios, it'd be an old Browning B.A.R. with plenty of extra magazines and spare parts. Because 20 rounds of 30-06 coming out of a fully automatic weapon tends to get things done.