Are you going to fly, take a train or drive?
Your question is incomplete. Each mode of transportation is governed by different laws.
You need to contact the Phillippine embassy on this matter to see if you can even import a firearm into their country legally.
I know of no gun registeration in Maryland. No such thing as a unregistered gun.
You will need the services of a lawyer
Depends on the gun. For most common rifle, shotgun, and handguns, MD does not have a registration requirement. Assualt weapons are required to be registered. Link below to MD firearm laws, and you can check with the MD State Police.
2812 miles
It is 2,707.41 miles according to MapQuest.
Any car can be towed regardless of stickers
Very generally speaking, a felon cannot have access to or control over a gun anywhere in the U.S.
It is 2,522 miles according to Google Maps.
The shortest distance is 2,668 miles.
Yes it is possible. But a pellet rifle will make a cleaner kill than a BB gun. BB's do not deform on impact and the rodent will suffer before death. Where a pellet will mushroom on impact and kill in a more humane way. Also, you should check with the wildlife commission first, because while Maryland does allow hunting small game with air rifles, they're required to adhere to all other rifle regulations... presumably including the one that "soft point ammunition" be used; I'm not certain that BBs (which are usually copper-jacketed steel) qualify.
Yes, but there is a 7 day waiting period in Maryland for handguns and "assault weapons" based on what I found.