give a warning when called-to test is about to be deleted

You said:

"keywordtest 2 calls keywordtest 1 (by using Run Keyword test command);
User deletes keywordtest 1 from projectexplorer.
Would be better if warning is displayed that keywordtest 1 is being used by keywordtest 2. "

I agree, we need this.

You also said:  

"And deleting test 1 would result in exception if keywordtest 2 is executed."

TestComplete already does this.