All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His Slave and Messenger.
We shall sum up the answer to your questions in the following points:
Firstly, it is incumbent on the person who suffers from incontinence to perform ablution for each obligatory prayer after it becomes due and then perform the obligatory prayer and voluntary ones, as he wishes, with this ablution. The Maalikis, on the other hand, held that the person who suffers from incontinence is not obliged to renew his ablution for each prayer; his valid ablution is sufficient as long as he did not invalidate it through any hadath (nullifier of ablution) other than the incontinence. The first scholarly view is the one adopted by Islamweb. Al-Mawsooʻah Al-Fiqhiyyah (Kuwaiti Encyclopedia of Islamic Jurisprudence) reads:
"Muslim jurists, aside from the Maalikis, maintained that it is incumbent on the person who suffers from incontinence, to renew the ablution for each (obligatory) prayer. The Maalikis, on the other hand, held that it is only recommended ... The Shaafiʻis and Hanbalis maintained that he should perform ablution after the time of prayer starts..."
Secondly, if the padding has become ritually impure, it must be washed and cleaned or replaced by a pure and clean one before performing the prayer because the purity from khabath (physical impurity) is one of the conditions of the validity of the prayer just as the ritual purity from hadath (nullifiers of ablution). If changing the padding constitutes considerable hardship, then, hopefully, there is no harm in performing the prayer while wearing it so as to ward off hardship and difficulty. Jurists stated that any impurity of which one finds considerable difficulty in taking precautions to avoid it is pardoned in the Sharee'ah. The Maaliki scholar Ad-Dardeer wrote, "The impurities whose removal and avoidance constitute hardship, such as continuous incontinence, are to be pardoned. The impurities that the person finds difficulty in taking precautions against are pardoned as far as prayer and entering the mosque are concerned..."
Thirdly, as for the inquiry regarding the permissibility of leading the congregational prayer, scholars held different opinions whether it is permissible for the person suffering from incontinence to lead the congregational prayer or not. Some scholars maintained that it is permissible and valid, while others held that he is allowed to lead only those who also suffer from incontinence. The scholarly view adopted by Islamweb is that it is permissible and valid for the person suffering from incontinence to lead the congregational prayer. Hence, there is no harm done if you lead the congregational prayer; nevertheless, it is more prudent to lead only those who suffer from incontinence in order to be on the safe side in terms of clearing you of your liability.
Fourthly, the Maalikis held that touching women does not invalidate the ablution, even if they are among one’s mahram (unmarriageable)women, according to the famous scholarly view in the Maaliki school, except in two cases: First, if accompanied with lust, even if unintentionally. Second, if intended to be lustful touching, even if the man does not experience sexual lust while touching. However, in case of touching without intending lust and no sexual lust is found, it does not invalidate the ablution.
However, there is no harm done if you follow the Maaliki views; that it is not obligatory to renew the ablution (for each prayer) in case of incontinence and that impurities that one finds difficulty in taking precautions to avoid are pardoned given the need; verily, such scholarly views are strong.
Allah Knows best.