Certainly everyone could agree that each of our rights come with restrictions. Hell, Conservatives themselves would openly welcome a drastic repression of our most fundamental right; that of free speech. What other political group could work for a flag burning amendment? "Stop, Question and Frisk" has been procedure for the NYPD and there was no opposition from Conservatives for that program.
But Conservatives cannot rationalize those repressions with a need for background checks and waiting periods! They are flexible on the 1st and 4th amendment in order to maintain public safety, but not the 2nd!
How would a waiting period have prevented ANY of the mass shootings mentioned? These were no spur of the moment attacks. These were well planned and prepared. So you are propsing something that would not prevent the problem. The same goes for background checks, which are already in place, and have been in place. background checks do not prevent someone who has just lost it if they do not have a criminal record, or a history of mental adjudication.
Also, people with libertarian leanings would never support a flag burning amendment, and oppose stop and frisk, so that dog doesnt hunt either. Liberatrians are the ones who mainly support gun rights, and this support is consistent with the other two positions, i.e. minimum goverment involvement in people's lives.
Rights can come with MINIMAL restrictions, and any restriction has to be based on an action that results in a criminal action. Yelling fire in a theatre when there is no fire, creating a panic is an action that results in damages and are thus punished. when people use a gun illegally, they are also punished.
Onerous restrictions on gun owners who have no intent or desire to perform a crime is like gagging everyone who enters a theatre on the assumption that they MAY yell fire and cause a panic.