The Levush explains in his commentary on Orach Chayim 581 (page 204 in the PDF linked here) why the selichos service concludes with kaddish shalem, which is normally reserved for after shmoneh esrei.
אע״ג שבכל ימות השנה א״א תתקבל אלא אחר תפלת י״ח שכן הוא משמעות לשון צלותהן שפירושו תפלה וסתם תפלה ר״ל תפילת י״ח שאני סדר הסליחות שנתקנו כולם על סדר התפלה של ...
There are indeed different customs regarding whether or not it is necessary / proper to recite Birkhat Hatorah prior to selichot. This clear and concise Halacha Yomit on the subject brings the major minhagim and their sources:
1) Maharshal writes that in Germany the custom was to rely on the opinion of Maharil who ruled that one need not recite the ...
Rema Orach Chaim 46:9 notes that the custom he observed was to recite birchot hatorah only after selichot.
However Mishnah Berurah 46:27 points out that the prevalent custom today is not to recite any verses before birchot hatorah, therefore one should recite birchot hatorah before selichot.
Artscroll (introduction to Selichot) quotes the Maharal of Prague as
writing strongly against supplications addressed to angelic advocates.
Why may one seek the intercession of human intermediaries [the avot
and imaot], yet be prohibited from beseeching the angels to advocate
his case? Man is commanded to perform acts of kindness with his fellow