Questions about getting patents?

Let's say I want to get a patent for a technological creation of mine. So I hire a lawyer to see if there are any other patents that would conflict with mine. He doesn't find any so I obtain my patent. I make the product and it hits markets where it begins to sell. After I start selling my patented product, another person contacts me and claims to have filed a patent before me which conflicts with theirs. Do you know what happens in this situation? Will it be my patent lawyers fault? Will I have to pay that person royalties?

Having done some patent searches I can tell you that it is NOT an exact science. Your attorney will give you a couple of pages of limitations and disclaimers, including the fact that there could be secretly filed patents somewhere in some country in some language that may not be discovered until after your patent has been issued. In other words, no attorney is going to guarantee there are not other patents that your invention might be infringing. Even a patent EXAMINER doesn't (can't) find all the possible prior art, although they do try pretty hard sometimes.

Bottom line, all it takes is one documented public use or published disclosure of your invention, dating from before your filing date (or date of invention), and your patent is worthless.

No, you could not sue your attorney unless you have proof that his or her search method and opinion violated the standard of care for such things as pass within the profession.

Yes, if you want to practice an invention covered by an earlier patent, you may need to pay royalties, since your patent on the same invention would be (a) void, or (b) severely limited to only those portions (if any) that do not infringe the earlier patent.