Can a defendant legally respond to a civil formal complaint denying “any and all allegations” when allegations include what should be indisputable facts such as their business name and location?

No, under court rules, you should admit what is obviously true or correct (and especially if it doesn't hurt you), and you also have to admit or deny line-by-line or allegation-by-allegation. However, you don't need to admit what you don't personally know. To give a quick example, let's say there are six allegations in a suit claiming that you breached a contract with a home contractor by failing to pay everything you owed (which you, in good faith deny). The allegations are:
1) John Doe [that's you] owns a home at 1313 Mockingbird Lane
2) Homes-r-Us is an LLC licensed to do home renovations.
3) John Doe hired Home-r-us to renovate his home.
4) Homes-r-us did all the work they were hired to do.
5) John Doe breached the contract by failing to pay Homes-r-us the amount legally due them.
6) Homes-r-us was damaged by John Doe's breach in the amount of $30,000.
Your position is that they failed to do the work and that's why you didn't pay them. You answer as follows:
1) Admitted [assuming they got your name and address right]
2) Defendant lacks sufficient information and leaves Plaintiff to its proofs [you don't know for sure that they are an LLC or licensed, but just know what they told you--let them prove this]
3) Admitted [if you did in fact hire them, it's true and you know this]
4) Denied [you believe they did not do all the work]
5) Denied [you feel you did not owe them all the money, because they breached by failing to do all the work]
6) Denied [you don't agree that you owe them $30,000]