Commission questions

Ok, assuming buying 1 lot eur/usd. One would need 130800$, but the value of one pip is 10$

so… if 5$ commission per 100000$, that traded translates to 5*(130800/100000)/10=0.654 pips

if 3.5$ commission per 100000$ traded, that translates to 3.5*(130800/100000)/10=0.4578 pips

Q1: Is that correct?

Q2: Are commissions => pips for other pairs raughly the same?

Q3: Commissiion is normally paid only once per trade? (Asking this because i see one broker stating that 2$ per 100000$, but pay both at open and close)

Q4: Which (serious) broker do you think has best offer? I am looking for something like 0.7 pip or quivalent without trading millions for majors.