You might be surprised how light leather can be. This is 2/3 oz vegetable tanned leather, so the Titan is probably 10X heavier, haha.
If you're using nylon, that fabric tape for the edges if fairly popular, as it can fray from the edges. From the US made nylon stuff I have that's made well, it looks like they put the two ends of fabric, overlapping, between the tape, then run two stitch lines for the length. So, probably oversize each panel so you have maybe 3/8" excess along all the edges.
Make sure, when you're sewing it all together, you sew it inside out. That will better allow you to pinch your edges and sew them with the tape.
For VERY SMALL SCALE situations, you can burn the edges of nylon. There are specialized tools that melt/cut edges (lasers being the neatest and most insanely expensive).
Another option, if you're adventurous, is you can go SUPER old school, and use cotton duck. You can heat up paraffin or bee's wax, and work it into the fabric if you want to waterproof it. It's a very traditional way of making satchels, holsters, etc, and then waterproofing them. Sometimes linseed oil was used (though, that almost always needs heavy metal driers, so not my favorite solution). For duck, people just kind of roll the edges and sew them, as it doesn't fray AS much, but there's still some technique to that sandwiching.
Velcro can work, but make sure you've purchased Velcro made to be sewn in. That should come on a soft fabric tape, and you can do a few different stitches to hold it: fully lengthwise in rows, box stitching (that seems to be best?), or I've seen people do a combo of stitched edges with box stitching along everything. Snaps are nice, but you want practice setting snaps, and either the cool, expensive press thing, or a quality kit.
I think I have these two snap components for line snaps.
The anvil:
OVERVIEW The universal snap setting base fits all the snaps we sell from (Line, Segma, Spring, Glove snaps) The base is made of polished stainless steel and has a nice heavy weight to it. The domed bases contour to the domed snap caps providing even pressure and protecting them from flattening...
www.rmleathersupply.com
What you hammer:
These Hasi Hato line snap setters are made in Japan and are designed to set the line snaps in both small and large. You will also need to purchase the universal setting base which has a flat side and a concave domed side. This helps you to set both the flat size of the snaps and the rounded cap...
www.rmleathersupply.com
You'd need a soft, solid mallet (I have a leather maul, but a leather hammer works well). You COULD probably use a wood mallet if you didn't mind mangling it up.
Some people insist you just SMASH that snap in one fell swoop, but I've found lightly tapping and "rolling" to start, and THEN giving a solid, firm smack works well.
Getting a scrap piece of quartz or granite to hammer on (maybe with a rubber mat between the stone and your table) helps a LOT to make sure the force doesn't just move THROUGH the snaps. I bought a granite cutout from a countertop place for like $40? It's heavy and kind of insane, but MAN does it make snap setting good. If you can get a smaller/broken piece, it might be cheaper. If you have a stone counter, you could probably just use that, though, I don't know if I'd love the risk of chipping it by hammering a steel anvil into it, haha.
But, don't be afraid to pattern with simple office paper. It's fairly flexible, and cheap. You can put your flashlight down on a "back panel" template, and then press the paper along it.
Leather is nice in that it CAN mold around corners/edges. I'm not sure how you handle that with fabric. As you can see from my pics, I sort of skirted hard edges by design, cause I didn't want to wet mold, and wanted a way for debris to drop out.