Imperial/Wilmington station is safe. The problem is that this station is sandwiched between freeway overpass and a busy road (you board the Green line on the 105 freeway medium) so it doesn't have much around it that you can walk to and visit. There is a shopping center right next to it with typical fast food option but it is not all that interesting. The neighborhood around it is a bit rough but not by any mean dangerous. You can take the train one more stop to 103rd street to visit Watts Tower if you want... you will come back alive, I promise
I would not worry at all during the day time.
Imperial/Wilmington is a major transfer station in the LA Metro system and you will see toruists from Downtown LA making transfers to Green line here. I use this train station on a regular basis and have never had any problems.