b) Can I work in all the countries in Europe with my Poland Work permit.
No, you have a permit to work in Poland, you would need a permit to work in any of the other EU countries as you are not an EU national.
c) Can I switch my job in Poland or other countries in Europe
See above answer.
Is there any condition like I need to be in Poland for 2 yrs., only then my dependants can join me.
Wouldn't you be best off looking at Polish government site to find this information out.
a) Can I visit all the countries in Europe with my Poland Work permit.
You may be able to travel in the Schengen zone, this does not include the UK.
ec.europa.eu/youreurope/nav/en/citizens/travelling/schengen-area/index_en.html#23297_5
Is there any condition like I need to be in Poland for 2 yrs., only then my dependants can join me.
Im sure you will be able to bring your dependents, but you will need to show you are able to support them fully, i.e. they will not have access to any public funds and Im sre that they will need private health insurance.