Although there are professional copy writers & content writers the basic contents comes from the key persons in the organisation which owns the website as they know the subject e.g. Products , Industry etc more than anybody else.

Results starts appearing in the 1st month or sometimes in the 1st week depending upon competition for Keywords & other factors, however for satisfactory results to appear it will take about a year once again depending upon the competition for keywords in that industry.

Technically there are no keywords which cannot be ranked, however due to stiff competition of keywords and lack of more keywords in some Industry e.g. Apperals Industry "Shirts", "Trousers", "Suits". "Tie" etc being common for every website will find it impossible to get a ranking on the 1st page.

There is no limit for getting external links for website, however the resources availble are very limited, most of the Directories which cliam to offer free links do not actually provide them. The paid links story is expensive and dangerous, they take payment online and do not provide what they have promised and you cannot trace them as they are overseas organisation. Further your Credit Card credentials are later used by them to defraud you. Beware of Paid Link Sellers.