yeah you should put some personal opinions in a research paper. If you put a whole bunch of time and effort into researching a certain topic, than you should develop some kind of feelings about it, right? If not, what did you really get out of the project. What is your reader going to take from it? Who wants to read a bunch of factual information about something without a little byist opinion? If it has opinion than the reader can decide if he/she thinks it's BS or not.