"Reverse" Importation Question

[GrayAnderson]

For obvious reasons, this is going to be the reverse of a lot of the questions on border-related stuff, but a lot of the same principles apply. I live in the US (Virginia, actually), but I can see a situation where I would want to come up to Canada for an airsoft match. I do not have a match in mind right now, but...well, paperwork being paperwork I'd rather ask and know than not ask and fail to find out until it is too late to get stuff in order. My questions are:

(1) With respect to airsoft weapons, other than the (rather amusing and absurd, at least to me) restriction that they need to shoot at least 366 FPS or thereabouts (or is it 407?), are there any restrictions I should consider?

*What size BBs should be used for checking this? 366 with .20s is obviously different than 366 with .30s.

(2) In connection with (1), is there any licensing I should look into pursuing? From what I can tell, I should be able to bring an airsoft rifle into Canada much the same as a hunter would (with all of the attendant paperwork including a proper US declaration...CBP Form 4457, I think) presuming that it would meet with the appropriate regulations. For a host of reasons, however, simply getting a proper firearms license might be the easier path to follow.

(3) In connection with (1) and (2), do importation rules differ with items being brought in on a temporary, rather than permanent, basis? I wouldn't normally ask this, but there's enough absurdity in terms of legislation on both sides of the border that it is worth asking. Likewise, would the possession of an appropriate firearms license have any impact on the ability to bring something across the border, either on a temporary or permanent basis? Everything would be "accompanied" both ways, and ITAR seems to have exemptions for things that aren't being exported to Canada on a permanent basis.

(4) I am sure there is a posting somewhere on here, but can anyone direct me to a good set of rules on what part(s) of something would need to be clear/what those rules are?

(5) In the department of "this idea of a law confuses me", how /do/ you end up with permits for "prohibited" items (i.e. airsoft retailers getting permits to sell airsoft weapons that would, at a glance, appear to be illegal to possess)?

(6) Ok, those might be the easier parts of this. I've also got a nice modern US kit and am working on a vintage Vietnam-era kit as well. In the case of the former, my read is that as long as I keep the hard plates at home (and keep a copy of form 4457 handy) I ought to be good. In the case of the latter, however...is there going to be any issue with dragging a nearly-50-year-old flak vest across the border? It doesn't have a serial number as far as I can tell (age is an issue here).
-This is part of why I would look into a firearms license...it seems that every province that pursued body armor restrictions except for Nova Scotia put an "if you have a firearms license you can have body armor" clause in their rules. I'll confess that part of this is, well, laziness...I still wince at how much of a pain it was to get the soft armor into the modern kits.

(7) In that vein, are there any other pieces of kit I should be wary about packing? I'm presuming "don't bring knives across the border", but is there anything else I should be aware of (ITAR-wise or otherwise)? Gas canisters shouldn't be an issue (I don't have any gas guns, for example).

(8) An addendum to all of the above is the fact that there are no circumstances under which I will be traveling by air into Canada (at least, as far as I can foresee). If I'm not bringing any airsoft weapons across the border, I'll probably be traveling by train; if I am, that probably forces me to either take a car or ship separately. Any advice with respect to non-air entry into Canada on this front (since what posts I've tracked down seem to be biased towards air entry)?

(9) And finally...would having a Canadian citizen with me help with any headaches? I have a friend who is a dual citizen (one side of his family is Canadian, one side US...and he was born in Asia, which makes for a lot of fun when someone asks to see his birth certificate), so if the cost of reducing a bunch of headaches is buying him a train ticket, so be it.

And yes, with all of the above I have seriously considered contacting an attorney for advice. On a few of these points I know I will inevitably throw up my hands and say "Not worth the hassle", but...well, as I said before, I'd rather ask questions and try to sort out answers when it is just a lark rather than waiting. If I have to rent a gun north of the border, such is life; I'll be a lot more sore if I have to completely ditch all my gear as well.

For what it is worth, I have poked around for answers and come up short...but a lot of that simply has to do with which way I am traveling (north vs. south) making most of the FAQs a bad fit.