The phrase "a host of important" is correct and usable in written English.
It can be used to refer to a large number of significant items, ideas, or issues in a particular context.
Example: "The conference will cover a host of important topics related to climate change and sustainability."
Alternatives: "a multitude of significant" or "a variety of crucial".
Scholars have long recognized the importance of leader member relationships for a host of important outcomes, including satisfaction, performance, and citizenship behaviors.
American and Russian leaders face a host of important security, political and economic issues.
Documents show how finance lobbyists won a host of important policy changes in Whitehall and Westminster.
George W. Bush's cabinet may look like America, but on a host of important domestic policy issues it sure doesn't think like America.
That is not true, and it deflects the conversation from a host of important defense issues that the candidates should be addressing.
I came out feeling my attention had been drawn to a host of important topics rather than having had my emotions fully engaged.
But it's not a large step from there to a host of economically important applications.
By the end of World War II he was regularly publishing cartoons in The New Yorker and a host of other important magazines.
Since 23 June it has become a host of hugely important consequential questions about access, rights and rules, all of which involve big principles and have huge economic, political and cultural implications.
He needs Beijing's help on a host of hugely important and extremely difficult problems, including stabilizing the global financial system, curbing global warming, prying away North Korea's nuclear weapons, and ensuring that Iran doesn't get to build any.
Virology is a discipline of immediate interest because many human diseases, including smallpox, influenza, the common cold, and AIDS, as well as a host of economically important plant and animal diseases, are caused by viruses.
