I am not a lawyer, I merely deal with them all day to an extent that I am now taking night classes to become one.
This should not be construed as legal advice but should provide enough information to answer your question.
If you are not actively disparaging their trademark or using it in a manner as to lead to confusion of commerce for an average person or falsely representing yourself as them, then you aren't likely to be sued. In order for Cedar Fair to have any sort of case they would have to prove financial harm or harm to their reputation. If you are merely recreating an attraction that already exists and are doing so in good faith then they really can't prove any damages occurred.
Now if you created a ride under the similar branding with a similar style and layout and made the ride kill everyone each cycle, which isn't possible in NoLimits, then they might have a case. They could claim that you are using their trade mark to place their business in a negative light. I would expect that before they did anything they would send a nasty gram. (strongly worded cease and desist letter) If they could not send it to you then I am sure they would serve it to us and we would forward it to you.
However knowing the amount of defensive litigation parks are engaged in at anyone time I doubt anyone would bat an eye. You also don't initiate litigation unless you know that you can get something out of it. In most states if you make say $40,000 a year with only a primary residence and a car then you are in most jurisdictions a judgement proof debtor. So they can't really get anything out of you even if they won so why waste the money. The courts also tend to frown upon large corporations filing cases against minors and the indigent or to use the courts to enforce a or silence a political agenda. In order to file in a court of competent jurisdiction it could cost them as much as $1,200 plus the lawyers fees. Not to mention they have to file in a jurisdiction where a court would actually have jurisdiction.
As long as you aren't making lots of money and you are doing it solely for the love of what you do, ala a Hobby. Then your fine. In the entire history of this website we have only received a single DMCA for a track. Skittles sent us one of those automated cease and desist letters because a user uploaded their logo straight from their website onto a track. The user took the track down, renamed it, and re-uploaded it. As far as I know nothing else happened and I doubt any human ever reviewed it.
If your interested in learning more about some of the legal concepts involved I would recommend you look up information on the following subjects.
http://dictionary.law.com/is a good place that explains some of these concepts.
<Insert Your State Here> Long Arm Statue
Trade Disparagement
Trademark Infringement
DMCA
Judgement Proof Debtor
Strategic Lawsuit Against Public Participation (SLAPP)