Should Liberals be thanked for helping the economy, through record high arms sales, after their rioting looting, arson and vandalism?  ?

I hope you're just speaking tongue-in-cheek, but in case you aren't:

You're talking about two totally separate groups of people here, and it's wrong for anyone (and this includes President Trump) to deliberately confuse the two in peoples' minds.

1.  One group consists of peaceful protestors who are acting in good faith to further their cause.  It is their constitutional right to do so.  President Trump has wrongly and unfairly painted a black picture of these good faith  protesters to the point that former Presidents Bill Clinton and George Bush came out publicly and praised them to counter the harm that Trump's fear-mongering is doing--they championed these peaceful protesters for exercising their constitutional rights following the death of George Floyd.   

You call them "Liberals" here as if 'liberals' are bad people?  But they're not bad people. They are  abiding by the law.  They are caring people who want their voices to be heard.  They cared that Floyd, along with many other black men, have been unjustifiably killed by police at a rate much greater than white men.  These protesters are not saying that 'all police are bad', either, because most policemen are good, responsible people respected in their communities.  But statistically it is true that blacks are more likely than whites to be treated harshly by the police and our justice system.

2.  The other group consists of crime-committers--crooks and trouble-makers--who take advantage of peaceful protests because they know that the large crowds of people give them a great cover for committing their crimes of robbery and looting

So don't confuse the two groups.  If theft and looting occur during peaceful protests, it's not the protesters who are doing it.  It's criminals who are out for themselves who take advantage of large crowds to do their dirty work.

PS:  REGARDING ARMS SALES:  Regarding your comment that 'liberals are helping arms sales' by rioting and looting? 

Are you trying to lay guilt on protesters, who are good people who care enough about violence against blacks, to speak out against the violence?  Are you saying that they should not have exercised their first amendment rights to protest peacefully because it sparked paranoid gun-happy Americans to buy more guns, that this burst of gun-buying is the protesters' fault?

That's distorted logic.  The peaceful protesters had nothing to do with it. 

If gun-happy Americans went out and purchased more guns 'to protect themselves' from peaceful protesters, then there's something wrong with the way gun-happy Americans think.  NO one can rightfully blame Black Lives Matter protesters for any increase in gun sales that may have occurred. 

Remember that 30,000 Americans/year are killed by guns and that this death rate has been going on for decades.  NO Americans were killed by peaceful Black Lives Matter protesters.