Increase max_entities (add at the very top of the main function):

max_entities = 8000;

However, you should never use that many entities as it would have a major impact on your frame rate.

It may say that it has 7105 objects, but this is not always true. I've had the count in my (otherwise empty and small) experimental level past 10,000 even though only 4 objects are in there. The best way to find out is to just build your level. It'll say "placing xxx entities". This would give a very good idea to how many entities you have. The exception is if you have a build error (such as too many portals).