Sorry it's taken me a bit longer to respond to your inquiries. I'll try my best to give some perspective.
1) " I think that many years ago it used to be that you could not touch the tent’s fabric or the water would go through that spot. I think that it was so because they were double wall tents and the fabrics weren’t as good as nowadays?"
While I can't attest to fabric construction back in the day, I can confidently tell you that this isn't so much a problem anymore with modern day fabrics that are only meant to be waterproof (as opposed to waterproof breathable, as seen in rain jackets). The major concern these days is brushing up against tent fabric and getting wet due to condensation that clings to the inside walls. This is a large concern with single wall tents like the double rainbow, and of very little consequence with double wall tents that have a layer of mosquito netting between you and the fly. It's something you'll just have to live with and be mindful of. In practice, it's not really that big of a concern, and merely one of the tradeoffs of having a lighter weight single walled tent.
2) The misting worries me a little although Ken says that it is not a problem for him. Konrad, could you tell me some more about it? Thank you to you both for the tip using hiking poles to support the structure. I did not know that. I do not remember the tent exactly but by using the poles am I minimizing the area inside the tent? Will the poles get in the way?
I didn't mean to scare you about the misting...it's really not as bad as it may seem. The best way that I can describe it is to imagine a water spray/mist bottle, turned to its absolute lowest setting--and then take only 10% of that output. In other words, you can feel a slight spray, but its very very very minimal. Silnylon sometimes has inconsistent treatment depending on the batch, source, year of production etc, so some misting cases might be better or worse than others. The misting by no means will get all your down gear soaked, or even remotely wet. For me, the its merely annoying as sometimes I feel it on my face and it keeps me up at night.
Using poles for extra structural integrity will not impede on the useable space, as the tent poles are used outside the netting underneath the vestibule doors. The poles will not get in the way of entry/exit.
3) There are different hooks and loops as well and I was wondering what someone can do with them. This stuff is not that intuitive to me. For example I did not know that I can adjust the hight of the tub (do not lough at me). I remember looking at it and thinking that it is low to the ground and that water is going to get in. It did not look like a tub to me.
Many of the hooks you see inside the tent are meant to be used with the clip in liner. I don't own the liner so I use those clips for lights, and to keep gear off the ground. Some people run lines between the hooks to hang wet gear etc.
In order to truly achieve a bathtub floor, you need to locate the clips OUTSIDE the tent, at each corner of the tent. Attach those clips to the stake guyline loops. See the photo below. It makes a world of a difference.
One of my favorite features of the tent is using the rain porch setup. Here's an example:
Also, as a general tip, I find that the main arch pole puts too much tension on the floor, causing this huge bunching wrinkle right down the center of the floor, resulting in minimized floor width. To alleviate this, I try to push in each end of the main arch pole towards the center of the tent (essentially decreasing the length of the tent a bit, but also adding more headroom by raising the arch of the fly) and keeping each end of the pole in place by setting a huge rock against it. See picture below (note the rock by the pole):
I don't own the liner, nor do I feel that it's necessary. The liner is meant to protect you from condensation drops (which is why it's to be used in humid conditions). I find that I'd rather save the weight of the liner by bringing a small shamwow and wiping down the condensation throughout the night or early in the morning.
I find tyvek to be too loud and crinkly, and instead, choose to use a lighter piece of window insulation wrap (polycro) cut down to size. Much lighter, and resists punctures well enough for weeks of use. Dirt cheap too.
My final tip would be to remove the cross strut before packing. It' makes it easier to pack and you can fit it into a smaller stuff sack this way.