But... even if you don't want to trademark it, a trademark search may still be valuable. Unless you are willing to risk that you may be using a name that someone else already trademarked.
Some thoughts on your "Mad Scientist Inc." name. May be you have thought about these already, but just in case:
A company named "Mad Scientist Inc." doesn't tell people what you do. You have to spend marketing dollar educating the customer and for a start up that could be money you don't want to spend. In later days after the company is established, it would be less of a problem but you are front-loading the issue.
Just as, "Dave Jones Inc." tells you nothing about what the company is about, "EEV-BLOG Inc." tells customers right off that it is a blog based company. The V will need some explaining "v for video" but at least that is a short explanation. I am sure you can imagine at the startup phase davejonesblog.com may be at a marketing disadvantage when compared to eevblog.com before people know who is Dave Jones?
Another case and point "RadioShack" - you don't need to look up what it sells. "Crazy Eddies" - you have no idea what the store sells unless you saw one of their TV ads.
Also, it would be best if the name invokes sentiments that promotes certain positive quality from people. Quality such as "good tasting stuff", "high quality stuff", "well designed stuff..." For example, the grocery chain called "ShopRite" (north-east USA regional) achieved two things, "Right place to shop", and using "Rite" instead of "Right" makes it more unique - less likely for the name clash with other existing entities. What does "Krogers" even means? Well, "Krogers" is another grocery chain but it is mostly mid-west USA regional. Name recognition isn't a problem now (not a startup) because most in town know "Krogers" sell groceries, but there is no "positive sentiment" associated with it. Perhaps in the business' town-of-birth, everyone in town knew the guy sells only quality meat (or whatever) so "Krogers" conveys quality. But when they first expanded say a few towns away, no one would know what/who "Krogers" is/was. Had the business started as "Krogers Fresh", it could have been very helpful in the getting going. Is "quality implication" build into the name necessary? Of course not, but why give away a chance to pre-bias your customer to your favor?
A company name can help you get more sales, or help you loose more sales. For example, "Christian Cakes" - well, may help you with Christians, but you may loose some muslim customers. On the other hand, "Faithful Cakes" may loose fewer. That said, if your business is to supply refreshment to Church Sunday Schools, that "Christian Cakes" may just be exactly the right name to go with.
So, you probably have to think from a business perspective about what message you want the name to convey.