ZDC Controller described an unsafe condition when providing OJT that was complicated by a photo mission aircraft.

Narrative

I was providing R-Side OJT during this session. We had around 5-6 aircraft inbound to IAD on the BARIN1 arrival. One needed to be sequenced into the flow which departed from ORF. I asked my trainee where he was going to put the aircraft into the flow. He turned the aircraft to BRV VORTAC without first assessing the situation and traffic flow; and hence projecting out. But that was not the problem. A VFR King Air was performing photo operations near the BRV VORTAC/FALKO way point on a north/south line pattern. First he was at 10;500. He then descended to 10;000; I presume to stay in VFR conditions. Either altitude is dangerous because our crossing restriction to PCT for IAD arrivals is FALKO at 10;000. I had to seize the frequency because the trainee fell behind and was not making the sequence work. I don't descend aircraft through known traffic; even if they are VFR. All our IAD arrivals were high coming into PCT airspace. During this time; the PCT Controller was yelling at me to get these IAD arrivals pushed down and switched to him. He was also telling me to get the VFR aircraft down to 9;000 and switch the aircraft to him as well; because he couldn't get his IAD arrivals down fast enough. So all the while; the Controller was yelling at me to do these things; I had to vector 4 IAD arrivals because the trainee fell behind the power curve on the sequence; and I knew he didn't have the experience or talent level to get himself out. Since all my IAD arrivals were high; it necessitated a point out to another PCT sector; FLUKY. Since I knew this VFR was just basically in the way; I asked the Controller at FLUKY to take a blanket point out; or Non-RADAR block at 11;000; for all these IAD arrivals that were high on their restriction. The Controller approved; so not only did I have the BARIN Controller yelling at me; I also have my Supervisor yelling at me that there are no such things as a blanket point out. Meanwhile I'm vectoring IAD arrivals to get at least standard separation of 5 miles; plus trying to explain to my trainee why he fell behind and I had to take over; etc. It became unsafe; when I was trying to provide the safe; orderly; and expeditious flow of air traffic; and I had a Controller on the shout line yelling at me; my Supervisor yelling at me; all the while I'm was just trying to listen to aircraft read backs. Also; the VFR aircraft had information about his route; but it was in the hands of PCT folks. They had to fax over the sheet to ZDC.