First of all,welcome to our forum brother.
Forgive me for numbering your queries pointwise so it benefits all.
1) Never happened with me.
2) Its a non issue.Excessive rains +wet/humid floor mats can do this to any car.In Fact it shows very good insulation,viz. not even allowing moisture in and out, and not poor insulation.
3) Min 10 years,if not 15.Mostly emotional reasons.You see I bond with my cars and two wheelers. I cried a lot after my Swift departure. Won't let this situation come again. Lots of heartache man!! After my swift was gone ,I realised what a big gap left behind in my heart. Call me mad but I will buy it back in a flash,if the purchaser is ready for it. I already have mentioned this to him!! He was smiling.
4) Ofcourse yes.It's a better car than TUV(not a proper 4 cylinder+sluggish) and ecosport(only a pretender,overpriced and funnily looks to be on stilts).But the most important thing--It touches my heart's strings!!Just like XUV,just like Swift,and just like my Discover Dtsi.