There is no inherent limitation on how "wide" your data should be to work within EG. Your first issue sounds like a problem that requires follow-up with tech support.
The second issue is probably due to volume and output format. 500 columns by 50 rows results in 25,000 table cells. If you are using the default output format of HTML, the resulting HTML result might be large and take a while to render. You can test this by setting your result options to use Text listing instead of HTML and see if the result appears faster.
One other note: Hotfix 5 for EG 4.1 addresses some performance problems with wide data. See
http://support.sas.com/kb/19/738.html.
Here is a SAS program that generates a simple wide data set, for testing.
[pre]
%macro makewide;
data wide;
%do i=1 %to 700;
length var&i 8 char&i $ 20;
var&i = &i;
char&i = "Column &i";
%end;
do j=1 to 1000;
output;
end;
run;
%mend;
%makewide;
[/pre]
Chris