You will get varying opinions on the above as the laws are poorly writen and open to interpretation. I will asume you are speaking about restricted firearms.
If you store them in a cabinet (like the tin stack ons) you will require they be trigger locked. If storing them in a "safe" they do not need a trigger lock. Some will say the stack on cabinet complies with the law. Others say it does not. I would not take the chance. It soes not need to be bolted down. So long as it can't be moved easily. Again a safe is very heavy and not easy to move. A small cabinet, or locker is and you could find yourself with an unsafe storage charge should they get stolen.
As for travelling. Your LTATT states what you can do. Basically travel from residence to any approved range in Ontario. You cannot stop at a friends for a BBQ. Now I have spoken to a few LEO, and they say common sense would say if your buddy is licensed and has a safe you would be ok. But it would be up to the LEO descretion. That's something I would not want to reply on when it comes to firearms. Most know very little about firearms and transport laws. They tend to charge first findout the right answer later.
If you are looking for more info a good source is a website called canadina gun nutz. Lots of good people willing to help others with their hobby. Just like this site.
Couple corrections...
there is no requirement in law that the safe be "difficult to move" ...A small safe weighing only 20 lbs, is legal under the law, even if its not bolted down.
An individual may store a restricted firearm only if
(a) it is unloaded;
(b) it is
(i) rendered inoperable by means of a secure locking device and stored in a container, receptacle or room that is kept securely locked and that is constructed so that it cannot readily be broken open or into, or
(ii) stored in a vault,
safe or room that has been specifically constructed or modified for the secure storage of restricted firearms and
that is kept securely locked; and
(c) it is not readily accessible to ammunition, unless the ammunition is stored, together with or separately from the firearm, in
(i) a container or receptacle that is kept securely locked and that is constructed so that it cannot readily be broken open or into, or
(ii) a vault, safe or room that has been specifically constructed or modified for the secure storage of restricted firearms and that is kept securely locked.
Rest assured, not matter what your storage preferences, if your guns get stolen, theres a good chance you'll be charged with unsafe storage...that's just the province/country we live in.
The LTATT issued under the auspices of the CFO (not the RCMP) covers routine stops for gasoline and meals. If you're buddy is not on a "reasonably direct route in the circumstances" you cannot go there. If you buddy is on the route, you can stop there for food. Me, I have a LTATT to gun clubs in Ontario and a 1 year ATT to all border crossings....so I am pretty much always on a reasonably direct route to the destinations covered on my ATTs.
Your friend doesn't need to have a safe, or be licensed. The firearm isnt being 'stored' there, so all that is irrelevant. The firearm is still in transport if you stop for a meal, leave it in the truck of a locked car, and you're fine. Just stay on a reasonable route.