Stoeger M3500 Disassembly/Lube Questions

I just bought my first gun as an adult, the Stoeger M3500. Owned guns as a kid but I never was the one to do the maintenance on them, but I read with this gone even Stoeger themsevles recommend disassembling and re-lubing. Many people say the sticky oil they use on their guns can cause jamming issues and should be stripped and replaced with something like Rem Oil. Why Stoeger doesn't properly oil them before they sell them to consumers is wild to me, but I went ahead with the procedure from this guide:

https://www.youtube.com/watch?v=Jf3QvLr_8zE&feature=youtu.be

No real issues doing it, except the trigger system locking pin I tried to put in the inertia bolt, but before I started banging the hammer on it hard I realized I had the wrong one and it didn't seem like a problem. And the boiling water trick was new for me, but I let it dry for some time. My only concern was maybe the magazine got a little water in it. It had some pretty thick lube in there so I just left it alone since instructions didn't say anything about it. Otherwise I am pretty sure I got everything else done just fine, it really wasn't that hard.

But I have two questions: the gun came with the barrel separated from the body of the gun, so I only cleaned the mechanics of it and not the barrel. How should I clean the barrel, or do I need to before i shoot it? Just use the same rem oil down it?

Also I'm sure I'm being overly paranoid, but since it hasn't been fired and i did disassemble it, should i be worried about firing it for the first time? I mean hopefully if something is messed up or done wrong it just doesn't fire, but curious if you guys fire a gun for the first time into the ground at the range or something before you put it up to your face, lol. I might be being wayyy too over the top about this, but wanted to ask. Thanks.

I have the M3K, the 3 gun version of the M3000/M3500. It's a great gun.

As long as you have lube on the the bolt and you reassembled it properly you should be fine.
It's definitely good to be cautious and safe with guns. In this case I think you're good to go.

The original "lube" is really an anti-corrosion coating rather than a true lubricant. Bear in mind the factory has no real idea how long it may be before the shotgun is actually purchased and fired; they can't have it rust in the box.

Since you reassembled the shotgun have you cycled the bolt and dry fired it? After checking that it's empty, of course. If the bolt cycles correctly and you can dry fire, you should be good to go.

As far as barrel maintenance, simply put a little oil on a pad and run it through the barrel every once in a while to prevent rust. Once or twice a season, get out the bristle brush and do a serious barrel cleaning; but there's no need to do it any more frequently. One area where you really should pay attention is your choke tube threading. On a regular basis, remove the choke tube and clean it. Clean the threading in the barrel, then lube both sets of threading well, preferably with a gun grease. Do not let your choke rust into your barrel.