Bismillahi Al-Rahmani Al-Rahim

Tahara: Wudu

Q1
''If a number of ritual impurities combine which require wudu or ghusl
and he makes intention for one of them with his purification, raises the
others." Please explain this. Also, if one simply intends in his heart to
perform the obligation of wudhu', does that suffice for all cases, or does
he have to be specific (I Intend to do wudhu' so that I may touch the
Qur'an, etc.)

A2
If someone has lost minor ritual impurity because of passing wind and touching their genitals, it is sufficient to make a single ablution for them both.

If someone intends to make ablution because it is recommended to have ablution for a given act, the ablution he makes is also sufficient for actions which require ablution. So if someone makes ablution because it is recommended to do so for reciting Qur'an, it suffices for touching the mushaf and other things which require ablution.

The quoted passage should read
If a number of ritual impurities combine which require wudu or ghusl
and he makes intention for one of them with his purification, it raises the
others.
        (m: please note the inclusion of "it")

And Allah knows best.

Q2
Are there any other provisions for wudhu', kind of like those listed in
'Umdat al-Salik?

A2
Yes. For example, there are eight conditions for ablution:
        (1) that whatever necessitated the ablution has ceased
        (2) the intention
        (3-5) that the person performing it is a Muslim, rational and has discernment
        (6) that the water be purifying and permissible to use
        (7) removing anything preventing the water from reaching the skin, such as wax and dough
        (8) having previously cleaned one's private parts using water and/or stones

Longer books will provide more details.

And Allah knows best.

wa al-salamu `alaykum
--musa