Where exactly did Moshe go?
Rashi: He went to within the three Mechitos, - Choshech, Anan and Arafel. 1
Ramban: Refer to 20:15:4:2***********
Rashi: Which was equivalent to the "Av he'Anan" mentioned earlier (19:9). See also Ba'al ha'Turim.
Why does it say "u'Moshe Nigash", and not 'Gash'?
Moshav Zekenim citing Pirkei d'R. Eliezer (41): Micha'el and Gavriel forced him to come close, against his will.
Why was the Torah given amidst darkness? It should have been given amidst light!
Hadar Zekenim: Hashem knew that they will serve idolatry, so He did not give it amidst light, lest He increase the Simchah.