If you’re visiting Christian sites, bring a Bible.
A water bottle, sunblock & a hat are recommended
A passport is a must to cross the border to Bethlehem.
Wear comfortable shoes . In Jerusalem’s Old City, dress modestly, Cover your  knees and shoulders.
Yes Of course.
I can Tailor make your personal tour.
NO.
Payment is made BEFORE the tour by bank transfer or Cash. USD$, Euro, or Israeli Shekel.
If you rather pay in cash, you can do it before the tour starts.
Credit card payment ,5% surcharge will apply.
Foreign checks aren't accepted .
Yes I am. According to Israeli law you must go through a long training process in order to guide visitors in the beautiful holy land. My license number is 8927.
It  rains only less than 50 days a year almost all between December and April.
Still- it might happen, there are solutions. Such as- Museums, markets, and of course-
in Jerusalem underground city.
Or you can simply bring an umbrella.

Yes and no.
For 1 day tours- no need!

Program of few days:
No – if the over night is in Jerusalem or Tel-Aviv.
Yes – if the over night is in the north, or in the south\ Eilat.
.

For most tourist it'll be better changing into shekels in Israel ( at the airport & hotels you'll get a bad rate) ,
There are many change points in the major cities and near tourist attractions.
Though most places will accept credit cards, you'll still need cash for tips, taxis, and small perches which aren't in the tourist markets.
I personally happy to receive Shekels US $, Euros or Pounds whatever is more convenient for you.