This answer applies only in the US- other countries have other laws:
Yes, you may purchase a firearm on line, without having a "gun license". HOWEVER- when a firearm is transferred across a state line, then that firearm must be received by a holder of a Federal Firearms License in your state. Translation- I have a firearm for sale, and you want to buy it. You send me payment, and a copy of the FFL from a dealer in your home state. I verify this is a valid license, and ship to that dealer. You go to the dealer, and complete the same paperwork you would complete if you were buying from that dealer. Dealer conducts a background check, complies with state laws for your state (as far as legal guns for your state, state license requirements, waiting periods, etc) When all of that is complete, you can pick up your gun.
internet purchases must comply with the same laws that a live face-to-face purchase will require. Unfortunately, some members of the news media have fostered the idea that a 12 year old can by a machine gun on the internet- and that is simply not true
It depends on your stste, but in 99.9% of the country you can. Check your local gun shop to be sure.
Absolutely ... there is no law where it states you can only store guns in a gun safe. You can put anything you want in any kind of safe.
That varies by state. Federal law doesn't require the issuance of pistol permits, but some states have written such a requirement into their state legislature.
Depends on state laws
No
yes
No it's not necessary.
No.
no
no
yes, you just need a license
Generally, no.
If you are looking to buy guns online, most places are safe since all transactions are legal and regulated. If the gun is going to be shipped, first will be shipped to the Federal Firearms License holder or FFL. The Federal Firearm License holder receiver will do the required background checks before the gun can be released to you. The FFL will charge you a small fee for this service.
No, I dont think you would need to have a licence for buying a airsoft gun but it may vary in what state you live in. I buy all my airsoft guns from budk.com
No, Only certain online tattoo supply shops require you to have a licence to purchase their equipment. But most don't ask.
If you'd be required to have a license to buy these items from a retailer, you'd still need the appropriate license to buy them online.