Sunday Telegraph Cryptic 2920

[Four Clubs]

Again please can you help me. 4ac Belonging to school, perhaps, that's cold and unfriendly (6ltrs) ?????h
5dn Sack worker, one often told to go to blazes (7ltrs) ????m?n
6dn Mean tip - it could make one poor as waiter (9ltrs)????t?e??
1ac Remove tax or duty (6ltrs) e?c?s? I think this must be excise but would like explanation, please.
16ac Allergic reaction a short distance into economic problem (12ltrs) i?f???m????? I think this must be inflammation?
15dn Financial result of putting artistic Frenchman over a railway (8ltrs) ???e???y - monetary??
Finally, hopefully, 23 ac Lesson is sorted out, in case (8ls) ??t?r??? - tutorage?
Many thanks. Four Clubs

[emeritus]

15 yes Monet a ry

[emeritus]

1a excise also means to remove

[emeritus]

5 fire man

[Four Clubs]

Many thanks, emeritus. Four Clubs

[emeritus]

6 impatient ...anagram

[Vulcanite10]

16a inflation with a mm (milli metre)

[vetuste_ennemi]

4ac of fish?

[fiction-factory]

of fish

[Vulcanite10]

4a FIRE MAN

[Four Clubs]

Many thanks to you all. Four Clubs

[cashier]

23. Tutorial. Out(anag) in trial

[Four Clubs]

Thank you also, cashier. Four Clubs

[DaveDisco]

I had 1a as Ex(or)cise. i.e. tax(take away) 'or' from the religious meaning of remove but it's the same answer