Cron -
One of the downsides to flying a pointy aeroplane is that the front is somewhat narrow, as you have identified. It wasn't too bad getting in and out, but it was easier for the pilots to get in before the FE was in situ.
Once in, it was fine. The roof and especially the side window was much closer than one finds in other types, but there was adequate space. It helped to be less than 6' tall (I'm not.....)
As for the engineer's space being 'spacious', well that's relative. It was a bigger space than the pilots'; however a few of the FEs were quite.....spacious.......themselves so they had the same problems as us.
Nick Thomas -
There were, as you say, baggage holds under the cabin at the front, and one aft of the cabin (the bigger one).
One would try to distribute the load to minimise any pre-take off fuel txfr, and especially to minimise any burn reqd (we're getting into a new subject here....).
Having done this one knew the empty CG and then managed the fuel accordingly. Min reserve fuel was 6500kgs and that was more than enough to manage landing and taxying CG. After landing a chunk of fuel was pumped forward for taxying purposes and there would always be ample for this unless one was seriously low on fuel (low enough for a 'Mayday' to be mandatory rather than just a bit tight).