Using roof basket 101?
 

I know it may be quite crappy place to ask about roof racks but I'm still gonna push my luck XD

So some time ago I purchased Thule Canyon XT roof basket for BRZ for some emergency scenarios when I'll need to transport some more stuff. Such scenario is about to occur next weekend (9 days from now) and I'd like to be somewhat prepared. I have few stiff flight suitcases AND few soft travel bags to take with me and I have several questions to roof racks and baskets users:

1. I have Thule roof basket elastic net - is it enough to secure soft bags and suitcases or do I have to use cargo straps? (if no, I've got 2 cargo straps, is it enough? How to attach those? I mean which axis)
2. Is it better to carry flight cases or soft bags on rack? (vs in trunk)
3. How do I weather protect stuff carried on rack? Am I supposed to buy some kind of generic plastic foil to cover stuff under net?
4. what are reasonable speeds to travel with bags in basket? My basket states 160 kph iirc empty but doesn't give any values for loaded scenario so I don't have any clue what is reasonable since I don't have any experience with roof racks. I heard roof boxes are fine up to 120-140 but it's a bit different story than basket.

Inb4 before everyone will suggest me to just rent a van - the whole point of this trip is to do it using brz with roof basket xD it's more of an "adventure" type of trip than practical point A to point B cargo transport. If I wanted to go A to B I could just get business class train and it'd be 8x cheaper and 2x faster because public transport in EU is quite good actually. I just want to have memorable, funny experience and get some memez material doing that xD Though I probably wouldn't like to end up with completely soaked all clothes in case rain decides to fall at some point because while it would be funny later on, I'm pretty sure I won't be laughing if I'd have to dry all of my clothes XD

Also keep in mind I'm asking about generic roof basket usage, not necessarily in the context of BRZ. If anyone ever used racks in their SUV I'm pretty sure the same practice will apply in my case as well.

1. i would definitely use cargo straps for security. at least 2-4, i've seen up to 8, just depends on how things are arranged.
2. i would shoot for hard cases in the rack, they should be slightly more weather resistant, also easier to crank the cargo straps down on.
3.most people use a tarp. just lay it between the suitcases and cargo straps, so the cargo straps do double-duty as load securement and weather protection securement.
4. just depends on load stability, and comfort level.

Yes use cargo straps. I would put them across the bags laterally, making sure there is pressure on each item. A tarp should be all you need for weather, make sure the corners and edges are tucked in and aren't going to flap around.