Extract all text without spaces and special characters

I have an ugly vendor database (around 50,000 rows) from different sources
and the names of the vendors look like this example:

ABC Company
A B C Company
A.B.C. Company
ABC Co.
Meridian Inc
Meridian Incorporation

I’m thinking in a formula that extracts all but the spaces and special
characters, in that way my database will look like this:

ABCCompany
ABCCompany
ABCCompany
ABCCo
MeridianInc
MeridianIncorporation


Then I can put a formula like =Left(A1,5) and that will give me common names
as:
ABCCo
ABCCo
ABCCo
ABCCo
Merid
Merid

My two questions a
1. How do I extract all but spaces and special characters?
2. I really want to extract around 7 characters and don’t receive an error
if the numbers of characters are less than 7. How can I do that?

Thanks for your help!!