Anything that has a value and is permissible to earn from, by selling or leasing for instance, can be set as dowry, even if it is a little. It can be a tangible item, or a debt that is becomes liable for, or a service, such as to sew a garment or recite the Quran. As for those things which are not permissible to make one’s earning by, such as musical instruments or pigs, it is not permissible to make them the dowry.
If he joins between the two prayers as in the question, he does not need to repeat the wudhu. If he separated between the prayers, he should do the wudhu again before the second prayer.
If the beginning of Muharram is the first day of your khums fiscal year then khums is payable at the end of Dhil-Hijjah, even if you started saving in Dhil-Qa’dah and did not save anything before that. The khums fiscal year begins when one gains any money in his life, even when he was a child. If you know that day then this is when you pay khums on any profit that remains unspent, even if you received the money days before this date. If you do not know that day exactly, then you should refer to the religious authority, i.e. the marja that you follow or his agents, to determine a day to be the start of your khums fiscal year.
It is obligatory on the father of the girl or her paternal grandfather to guard her welfare in accepting the marriage or refusing it. If the guardian in this case sees that the best interests of his daughter is not to marry this person, then he is permitted to refuse.