Help with the name of specialists (and others) – again?

Help with the name of specialists (and others)?
Please help with the answers to these. They all have to end with ist. Sorry i know i’ve posted this already, but i only got one answer.

1.a specialist in gardening and landscaping
2.a person with a gloomy outlook on life
3.a person bright and happy and hopeful outlook
4.an expert in language and languages
5.a specialist on rocks and earth science
6.a specialist in foot aliments
7.one who studies plants
8.a bee-farmer
9.a person who have two wives or husbands
10.a person who writes books for fiction
11.a person who runs a property with sheep or cattle
12.a specialist in the treatment of diseases by physical methods such as massage.
13.a collector of postage stamps
14.one who goes by pedal power
15.a person who indulges in the criminal lighting’s a of fires
16.a specialist in the treatment of teeth
17.a person who writes for newspapers of magazines
18.a person who plays a certain keyboard musical instrument
19.one who draws or paints with great skill
20.a specialist in the pharmaceutical trade

1. Horticulturalist
2. Pessimist
3. Optimist
4. Linguist
5. Geologist
6. Podiatrist
7. Botanist
8. Apiarist
9. Polygamist
10. Fictionist
11. Pastoralist
12. Reflexologist
13. Philatelist
14. Cyclist
15. Arsonist
16. Dentist and Orthodontist
17. Journalist
18. Keyboardist, Pianist, or Organist
19. Artist
20. Pharmacologist