Naturalisation and citizenship in Poland

I suppose you do not have Polish ancestry, so basically, you can claim citizenship in Poland after:
• Living legally in Poland for 5 years – be it by studying or working
• Getting married / having a child with a Polish citizen

For each different way, there's a different bureaucratic / formal process, and as far as I know, you don't need to give up your current nationality.

The advantages of acquiring Polish nationality depends on what you want/need. With that, you'd be able to live and work in any European Union country. But if this is the only goal about having Polish citizenship, keep in mind that you'd still have to stay in Poland for 5 years before having such rights. So, in practical terms, you you get to the point to be eligible to get this new citizenship, you'll have already almost all the rights inside Poland but the Polish Passport.

after 5 years you can only get a [permanent Residence permit, not citizenship.  Unless you are a spouse of course.

Once you get Permanent residence permit, then you need to wait for a further 10 years to get citizenship

What are the requirements for acquiring citizenship in Poland? For example, length of residence, language requirements, employment etc..
--> note that they change the rules every now and then.
the rules are kept here -- http://www.migrant.info.pl/how-to-obtai … nship.html
Recognition as a Polish citizen shall be granted to:

a foreigner residing continuously in Poland (what is an uninterrupted stay?->) for at least 3 years on the basis of a permanent residence permit -> or a long-term EU resident permit -> and who has a stable and regular source of income in Poland and legal title to the occupied dwelling->;
a foreigner residing continuously in Poland (what is an uninterrupted stay?->) for at least 2 years on the basis of a permanent residence permit -> or a long-term EU resident permit  -> and who has been married to a Polish citizen for at least three years or holds no citizenship;
a foreigner residing continuously in Poland (what is an uninterrupted stay?->) for at least 2 years on the basis of a permanent residence permit -> which was obtained in connection with refugee status granted in Poland;
a minor foreigner with one parent who is a Polish citizen residing in Poland on the basis of a permanent residence permit -> or a long-term EU resident permit ->, and the other parent who does not hold Polish citizenship has agreed to this recognition;
a minor foreigner with at least one parent whose Polish citizenship has been restored, if the minor resides in Poland on the basis of a permanent residence permit -> or a long-term EU resident permit -[gt] and the other parent who does not have Polish citizenship has agreed to this recognition;
a foreigner residing continuously and legally in Poland for at least 10 years (what is an uninterrupted stay?->) who meets all of the following conditions:

What formalities are involved in the process?
- loads of formalities.
- language needs to be at B1 level at least

What is the policy on dual-citizenship in Poland? Do you have to give up your former nationality?
- Poland's policy is basically "we don't care what other nationalities you may have.  if you have polish citizenship, we ignore everything else" -- but, going by your name, you are Indian -- India does not allow dual citizenship

What are the advantages and benefits of acquiring Polish citizenship, in your opinion?
- Advantages: you can travel around more and work in more places.  If your family is in Poland (as mine is), it is only logical to get Polish citizenship
- disadvantages: if your family is not in Poland, it probably doesn't make sense to get citizenship