i know that but GI has tighten up their restore function to the point where a tag in the game identifies the computer, google account and version last saved. Any change could mean that you can be accused of time travailing.
the game is linked to your goiogle account not to a computer. It does not matter if you use that computer or a different one. GI will know because it will not match the time stamp oin their server from the last saved game.
Later on where are you going to find space. Try to put them in an out of the way corner with no roads until needed. It is better then paying to store them and then when you need them you have no space available.
blimp or airship as you call it will be very necessary when you reach upper levels. Fuel station is a required building for upper levels. Other building you currently find useless maybe required later.
GI does have some useless buildings but most serve to drop items or are necessary for quests.
it means the surrounding area for x units gets the benefit. As you know each piece of land consists of 4 X 4 units
if you have a 2x2 building with a gift radius of 1 . it means the 12 units around the building get the benefit of the gift.
when paying for the bonus option you can skip 5 levels at first and then continue with one level uuntil ouu finish level twenty. but the cost will be around $ 15.00 Canadian..
Most people use this option when theyy are at level 13 or 14.