What is the Torah referring to when it writes "u'Shemartem es Divrei ha'Beris ha'Zos Va'asisem osam"?
Sanhedrin, 99b: It is referring to teaching Torah to others - and it teaches us that if Reuven teaching Shimon's son Torah it is as if he made him into the person Hashem created him to be. 1 Moreover, since we can read "Osam" as 'Atem', it is as if he made hiimself.
See Torah Temimah, note 3.
What are the connotations of "Lema'an Taskilu"?
Seforno, Ibn Ezra, Targum Onkelos and Targum Yonasan: It means 'in order that you succeed' (both as regards the world to come and in this world - Seforno). 1
Ibn Ezra: Like we find in Shmuel 1, 18:15.
What are the conotations of "Lema'an Taskilu es Kol asher Ta'asun"?
Refer to 29:6:1:3.
Lev Eliyahu (Shemos p.159): It means that, through guarding the Mitzvos, you will come to perform Mitzvos with added knowledge and understanding, which in turn, brings to more knowledge.
Avodah Zarah, 19b: It means that if one studies Torah diligently, all one's business ventures will succeed. 1
See Torah Temimah, note 5, who suggests that the word 'Nechasav Matzlichin lo' should be replaced with 'Derachav <i>Matzlichin lo' - that one will succeed in all one's endevours.