Good luck with copyright issues on:
2) Exact replicas of copyrighted technologies, (ie KAC's free floating RAS systems, RAS II, ARMS, SIR, etc)
The reason why these products DO exist on the airsoft market is simply because Taiwan (the manufacturing country of origin for most of these parts) has a loophole that allows them to bypass all copyright laws.
If you're going to do it, do it small scale enough that you won't get noticed, otherwise, have it manufactured in Taiwan and import it to Canada for sale. The alternative is to get legal licensing, but that WILL cost a lot of money.
To put some things in perspective: the reason why almost all manufacturing is done in Asia (China and Taiwan especially), is because it's extremely cheap there. It will be extremely difficult in Canada to get a machine, someone to put in the time to set up all the blueprinting and G-coding, raw materials, tool bits and tooling AND turn a profit and still provide a product that is cheaper than what Taiwan can churn out.
To get a higher margin, consider CNCing dies and moulds that you would be using to die-cast slides from. You lose the "CNC is cool" factor of your slide, but even the cheapest Asian CNC slides run just under $200 Canadian.
Even those CNC'ed mechboxes that were made in the states costed $250USD each, and that was with a run of 100.
Can you afford to do a 50+ quantity run of each gun that comes into question in order to make the R&D worthwhile?
Can you afford the monetary and time constraints of having to deal with the legal ramifications when it comes to replicating copyrighted products?