is learning without ameilus considered bitul Torah?

1) Rashi famously comments that אם בחקותי תלכו refers to ameilus in Torah.  Why ameilus in particular -- maybe the pasuk is referring to limud haTorah?  The meforshim generally go in one of two directions.  Some say Rashi was medayek in the pasuk's use of the word תלכו (see Gur Aryeh).  As my wife's grandfather explained (see her post here), one can only progress and grow, as connoted by the term הליכה, through hard work.  Others say Rashi was medayek in the pasuk's use of the word בחקותי.  The root of the word is חקק, to engrave.  Engraving is hard work and toil (see sicha of the L Rebbe on this Rashi), and similarly, it is only hard through work and toil that words of Torah will engrave themselves upon a person's heart.

R' Shteinman in Ayeles haShachar has an amazing safeik  whether learning without ameilus constitutes bitul torah.  I certainly hope the answer is no! 

2) Is ameilus a kiyum of talmud torah, or is it a seperate kiyum in its own right?  He quotes Menachos 7 which tells us that Avimi forgot masechta menachos and he travelled to his talmid, Rav Chisda, to relearn it.  Asks the gemara: why didn't he send for his talmid to come to him?  Answers the gemara:  סבר הכי מסתייעא מילתא טפי, he thought he would have more success if he did the travelling.  Rashi explains: משום יגעתי ומצאתי  Here you have ameilus for the sake of learning, but it is not the ameilus of breaking your head over a sugya.   The ameilus of breaking your head over a sugya is t"t, but travelling to go to the shiur may be it's own kiyum.  (I am not sure what the nafka minah would be.)

It's interesting that in that sugya Avimi made the job harder for himself than it needed to be -- he created the יגעתי ומצאתי even though there was a way around it.  Is there a mitzvah, for example, to look up every difficult word in a gemara using a dictionary rather than read the sugya in an English translation just because the former is more difficult than the latter?  Or do you get more schar for taking a bus to a shiur because it makes the trip harder than just driving?  Seems like a strange conclusion.