1st post:
1: "Frachtstempel" -> "Freightstamps".
2: Fire insurance.
3: Stamp for "Wechselsteuer" - a tax you had to pay if you transferred money at a bank.
2nd post:
1&2: Fiscals. Don't know what for.
3: A stamp used to pay "court fees".
3rd post:
1: No idea. Some "community- and state-worker's association".
2: Disability insurance.
3: Fire insurance.
4th post:
1: Bavarian railroads.
2: Don't know.
3: Again a "Wechselstempel". Same as post one picture three.
5th post:
1&2: Wechselstempel again

Number 2 says that 1,50 Mark was the fee you had to pay for transferring from 2000,- to 3000,- Mark.
3: "Rückvergütung für die deutsche Presse". "Rückvergütung" for the german press. A "Rückvergütung" is money you get back, if you buy faulty goods and return them, or similar. I have no idea how this was used in the press, though.
6th post:
1: "Gerichtskosten" - "court fees" again. Only valid in Hesse.
2: Same as above, but only valid in Berlin.
3: Fiscal.
7th post:
1: A fiscal from a police station in Berlin

2: No idea. I think it says "2. Hambg" on the right, maybe it's something from Hamburg, maybe from the port? This is just a wild guess.
3: Same as post three picture one.
8th post:
1: Private post parcel stamp.
2: Private post.
3: Again "Wechselsteuer".
9th post:
1: Bavarian fiscal.
2: Prussian fiscal.
3: Customs fiscal.