When questions are invasive, you should use judgment in whether to answer fully, limit your answer, or decline to answer. No one can tell you how much to open up. Each person has his own comfort level with nosy questions.
Not all invasive questions are unwelcome questions. They may be leading up to a more important question.
"Do you live alone" ... "Do you have a boyfriend" ... "Do you live with your parents" - these are all questions a guy might ask when trying to decide to ask you out. You could say yes, or no, or tell him you would rather not get into the personal stuff.
You also have to think about your privacy and security.
Sometimes questions are way beyond what is acceptable in everyday conversation - "have you ever been pregnant" or "do you like to wear a red thong" - and you just have to say, "That is not an appropriate question. Please drop it." Continued invasive questions after a warning constitute sexual harassment and generally should be documented and reported.
You can ask any questions you like about Doctor Who or David Tennant, and if someone knows the answer, as long as the question is not invasive of his privacy, someone will post the answer.
ignorance and being unable to trundle along.
invasive
they are invasive WEEDS
Yes, killer bees are an invasive species.
No species is inherently invasive. Rattlesnakes are found through much of North America, where they are not invasive.
Pandas are not an invasive species.
The opposite of invasive is non-invasive, leave alone, surrender, withdraw or yield, depending on the conext.
An invasive animal
A noxious weed is another term for an invasive plant species.
Invasive they destroy crops
some varieties are mildly invasive.