Exchanging of gifts on the occasion of nikaah

Q: I heard from the honorable Ulama a hadith regarding nikah. Nabi Muhammad (صلى الله عليه وسلم) said: 

أعظم النكاح بركةً أيسره مؤنةً

The most blessed nikah is the one which carries less expense.

So in this hadith Nabi (sallallahu alaihi wasallam) encouraged the ummah to spend the least on the occasion of nikah. I would like to ask you a few questions regarding the 'Money Spent' in Nikah.

1. What type of expense is referred to in this hadith that should be kept least to achieve the maximum barakah (benefit) of nikah?

2. Does giving gifts such as clothing, perfumes, etc. to the groom's family before the nikah ceremony fall under the category of nikah expenses as mentioned in the hadith?

3. Does holding a feast for the groom's family and brides close relatives after the nikah, at the time of rukhsati, fall under the category of 'nikah expenses' as mentioned in the hadith?

4. Does gifting the groom's family with garlands, flowers, and sweets after the nikah as a way to express happiness fall under the category of 'nikah expenses mentioned in the hadith above?

5. Should all these activities mentioned above be avoided to achieve the blessings of nikah?

6. If the bride's father is wealthy enough to carry out the expenses of such activities like giving gifts, holding feasts, etc. and does it happily without having the niyah to show off but just to express happiness,will this approach be against the hadith of Nabi (sallallahu alaihi wasallam) that encourages us to spend the least on the occasion of nikah?

Using a wet tissue when making istinjaa

Q:

1. I want to know if wiping with a dry tissue then wiping with a wet tissue during istinjaa is okay before making wudu and praying because I read that using a wet tissue spreads the najasat. What if I wipe with a dry tissue first?

2. I notice sometimes that the water from the toilet seat splashes back after I flush but I am not certain if it came to me or not, so is this water najis?