For what it is worth, both sides offer whatever evidence they think helps their case. It can be used unless the other side objects and then the judge decides. This only happens at the pre-trial if the judge decides to pre-admit evidence or there is a motion in limine. Otherwise, evidence is offered during the trial. But without legal counsel to help you, I doubt this answer makes much difference.
This is not legal advice. You should always discuss the specifics of your issue in person with an attorney. Be aware that there are time limits on all claims that depend on the kind of claim, so do not delay in seeking an attorney.
This is one of several questions I think you have posted on AVVO about your lawsuit. But, there is no way that the attorneys on this site can give you enough information to prosecute or defend a lawsuit on your own. You would be just as well, even better, going to the Dallas County Law Library and sitting down with a copy of O'Connor's Rules of Civil Trials and O'Connor's Texas Causes of Action, or the Dorsaneo litigation series, and try to puzzle through it. Of course, the best advice is to get an attorney because unless you really know what you are doing, more than likely you will never get to present your evidence at trial over the other attorney's objections.
I am licensed only in Texas. Offering information of a general nature in response to a question is not intended to be legal advice in your state.
I agree with Messrs. Arbuckle and Armstrong. No matter what happens at the pre-trial conference and no matter who says what, if you do not have a lawyer and your adversary does, your chances of winning the lawsuit at trial are practically nil.
You cannot learn the law or how to prosecute or defend a lawsuit on this or any other website. Lawyers study and work for years to learn these things.
Please consult a lawyer now, before it's too late.
Trying a case is not at all like completing a paint by numbers set. You can't learn it over the internet, no matter how many questions you ask. Even if you were able to learn all the rules of procedure and evidence, and understand the law, experience makes a difference. I probably couldn't do your job well, either, if I tried to learn it this way. If your case is worth going to trial, it's worth getting professional help.