Following up and in strong agreement... Slotted screws only, with slots aligned horizontal on gunwales, vertical on stem bands, etc. In other words, align slots parallel to the lines of the structure. In long decks where deck panels are fastened with screws, for example, align slots with gunwale. I hate seeing square-drive and Phillips screws in old wooden boats, except where originality requires. The Willits brothers began using Phillips at one point and Penn Yan used Frearson, so I use those as appropriate.
Some people frequently denigrate slotted screws because (especially in brass) slots can be buggered up, and in any metal, screwdriver tips can jump out and damage wood. Careful, thoughtful installation is the key, along with good screwdrivers. I use a nice set of parallel-tip screwdrivers (not wedge-shaped like most screwdrivers). These things seem almost magical. It's amazing that even in screwdrivers, a really good set is very well worth the investment. And with hand screwdrivers, you have control, you can feel what you're doing. It is tempting to use a drill/driver, but this is a good way to end up with damaged wood adjacent to the screw.
About making brackets for the stem/deck/gunwale junction, to me this is unnecessary and potentially harmful over-engineering. I prefer the cleanliness of original construction, and countless canoes have survived well the way they were built. I see lots of rot in the ends of poorly-cared-for old canoes, but not traumatic damage caused or allowed by the usual, simple original joinery of these parts. So the simpler, original joinery works just fine. More junk up in the ends of a canoe may trap more moisture, causing/accelerating rot.