I got some questions from a ABAQUS simulation, but since I don't see any abaqus foru and FEA theory issues in independent of the software used, I asked them here.

I meshed my solid and completed the job. However, I have few questions:
1)The job was running for hours and never stopped. So, I had to press on results for the simulation to complete successfully.
I got realistic results when I compared with my hand calculations. So is it okay to press on results whilst the simulation is running and take the output for comparison of results.
2)The For my structure, surface area of 8 sq. metres, and shell thickness of 5 mm, I used smalleet element of 5 mm, predominantly quadrilaterals but also triangles. Can these significantly small mesh on a large surface area justify the big computational time for running the FEA? Should I use bigger elements on the inside and smaller ones only at the edge?
Do you think there are singularities (see below)?