And my second question is - If i get work visa, can i immediately apply or have to wait?

You have to work at least 2 years in Cyprus

so no chance of being on dependent visa even if i am in Cyprus for 15 years!

1) You have been in Cyprus for 15 years — under what status? Why do you need a dependent visa now? 2) There is no fast-track visa, but there is fast-track citizenship through naturalization for high-skilled employees of companies with foreign interests (BCS category). More information can be found at the link provided above. 3) If your husband meets the criteria for fast-track citizenship through naturalization, he can apply. 4) You can apply for citizenship 3 years after he becomes a Cypriot citizen.

Thanks for your reply. I have been in Cyprus past 15 years on family reunification visa so couldnt continue my work here. Now i wish to apply for citizenship as Cyprus has become our permanent place. My husband works here and his high demand work does not give him time to learn greek. Can you elaborate more about BCS category?

https://www.cypruslegalservices.eu/residence-cyprus-foreign-interests/
The BCS category, if applicable, will be stated on your husband's residence permit.
In any case, fast-track citizenship through naturalization requires Greek at a minimum of A2 level, as well as an exam (in Greek) demonstrating sufficient knowledge of Cypriot culture and the social and political landscape of Cyprus.
You can also apply independently under the standard citizenship through naturalization procedure, but this requires (among other things) Greek at B1 level and the culture exam. You can easily research the requirements online