She said in her post....."I will be applying for the 6 month tourist visa instead, and am worried that they will deny me the visa (even though I will have all of the appropriate paperwork) due to having many stamps in and out of Thailand in the past few years in this passport"..........The answer to this question....is YES, get a new passport. What happens on arrival at the airport is a whole nother story. She only asked about getting the visa and for that getting a new passport will 100% improve her chances of getting that visa. FACT :)
Never fake a stolen passport as you have to lodge a police report and it goes on the system that you have lost a passport. This can cause issues. Not that I am commenting or promoting this at all, but a damaged passport has to be replaced....