Ok so your in NSW and your new to shooting welcome you will have fun.I will try to answer your questions in point form .
1. no you do not need to bol a 150kg safe to anything unless it has pistols in it then if it say 2 ton you still have to bolt it .
2..there is no cheap way out if you would like a safe that's ok . first safe i would look at is a spika shc1 comes in at 155kg your going to pay for it about $1200 min
3 for your first gun get a .22 NOT .223 you will learn how to shoot cheaper .223 ammunition is round about $25 for 20 rounds .22 is about $ 75 for 1500 when you can shoot and if you still like it move up to a .223
.416 Barrett good luck with finding ammo you can get turned projectiles $78 for ten then load them in your own cases then find a range that you can shoot them at .
4 Schedule 1 Prohibited Firearms 11. number 3
A firearm, not being a pistol, fitted with a stock that is specially
designed so as to be readily detachable, or to operate on a swivel, folding
or telescopic basis. even if its pinned the pin can be removed
https://www.police.nsw.gov.au/__data/as ... l_2013.pdfYes start small and work you way up to the big stuff when you know what to do with it
Stafford 98 is the 98 the year you were born?
I have not found a range that lets 416 on you will need private land and you rock up and ask a bloke to shoot with a 416 goodbye and most blocks would be too small for it . the shot may go over the boundary .
Most people when they start think they would like a large caliber till they fire one and find out I can only shoot 5 shots then it hurts small and precise placement are more important when starting out then as you learn move to slightly larger when you can handle it most people at the range when you starting out will let you have a shot of something bigger when you get chatting to them on the firing line .
Give it a go its a good sport I shoot at St Mary's at least once a week for the same reasons as bret plus you will never stop learning