SSMS version has nothing to do with the Instance version - they are 2 independent products.
you could easily be using SSMS 2017 with a 2008 R2 database

So...

from the licensing terms at https://docs.microsoft.com/en-us/sql/ssdt/sql-server-data-tools-license-terms

Installation and Use.

  You may install and use any number of copies of the software on your devices to design,...

Setting compatibility mode is a database level permission (alter database) if not mistaken.

create user is securityadmin or alter any login (no need for sysadmin)

CLR is...

only differences between Developer and Enterprise is that the enterprise version may be limited by the number of cores it uses.
If for some reason the Enterprise version used is...

On the particular sample of data you supplied it seems that everything field is within double quotes without exception.

That being the case would it not be an easy...

try changing the header delimiter to LF - there is a discrepancy between the header and row delimiters.

And what I have found before is that where there is...

I would say it may require one of the following

sysadmin - but should not be granted
dbowner - should be avoided
view definition (database level) or view any...

Regarding the links that Jeff posted be aware of some of the issues with it.
Firstly the Attunity driver is only for Enterprise Edition.

As for the driver itself.

are both same exactly the same spec?

mainly memory but also
number cores
size of databases - are they same size as prod? - having one or more tables...

does this work? without setting location

get-item "\\pathToPolicyfiles\policy.xml" | Invoke-PolicyEvaluation -TargetServer "servername"

look at https://docs.microsoft.com/en-us/powershell/sqlserver/sqlserver-module/vlatest/invoke-policyevaluation

Although the examples there do not use a network share, the Get-ChildItem can get them from there with no issues, and you pipe the file onto...

but ...

DECLARE @T table (data char(1))

Insert @T (data) values ('A')
Insert @T (data) values ('a')
Insert @T (data) values ('B')
Insert @T (data) values ('b')