I am not a roe expert but I'll offer my 2 cents. It is worth mentioning that if you search for something like "roe" in general discussion on this site you will find a few good threads from past years. Lots of good info. Also look at buying the book "egg cures." It covers most of what you asked.
My answers would be:
1- Yes chum roe works fine. In fact it is considered by many to be the "best" roe. My fav is chum roe. I like the way it looks (size and appearance of eggs) and it seems to fish well. And yes all roe does in theory work. Coho, spring, pink, steelhead, and so on. I've never had much luck on pink roe. I like spring or chum, but that's just me.
2- Best to cure it THEN freeze. Uncured roe is likely to burst in the freezer. Cured roe will not burst BUT, you need to make sure it does not get freezer burned. If you are not going to fish your cured roe right away put it in a container, roll it in borax, and make sure there is a good layer of borax on top of the roe. Use lots! It is cheap and effective. Some guys will vacuum seal jars, or vac seal in bags, and so on. Many diff methods! Id say keep it simple and freeze coated in borax with a layer of borax on top.
3- The meshy cloth is roe sack cloth. Just a different way to fish roe. Most ppl will tell you "loose" roe, like what you have, will catch more fish, but you go through a lot more roe as it falls off the hoo more easily. Whereas in the sack it says on much longer. But tying up the sacks takes a fair bit of time/effort. Personally I like sacks for steelhead as I don't need to rebait very often. If fishing for fall salmon I don't bother with sacks, I just use loose roe and cut it into fishable size chunks.
Also eggs in sacks you buy are typically "single" eggs that are salt water hardened. This is a can of worms and I'm not going to explain the whole thing.
4- IMO if you are not going to fish the bait soon you are best to cure it. And even if you are going to fish it soon, uncured eggs are very hard to keep on your hook! Yes they can go in sacks uncured (common for sturgeon) but for salmon most guys cure them up and either freeze them or fish it right away.
In short, get some roe, cure it up that day, when done either fish it tomorrow or freeze it in borax. When you plan to use it take it out of the freezer the night before and thaw it in the FRIDGE (nice and slow). Unused roe can be tossed back in the freezer in borax.