the enormous power of even one good deed

1) “Vayirarcheihu vayomar re’eih reiach b’ni k’reiach sadeh asher beiracho Hashem…”  It first glance it would seem that the bracha given to Ya’akov begins with the words “v’yiten lecha…” and the description of the fragrance (which Rashi explains to mean the fragrance of gan eden) of Ya’akov’s clothing is background information.  Yet that’s not what the text says.  The word “vayivarcheihu” comes before the description of that fragrance, not after it, indicating that it too is part of the bracha. 

Seforno explains that a field provides food for animals, maybe a place for them to live.  The beautiful fragrance of the field is not strictly a functional necessity – it’s an added gift for the neshoma to enjoy (the gemara learns the obligation to make a bracha on smells from the pasuk of “kol haneshoma te’hallel K-h).  The same is true of everything else – there is a pnimiyus to the world that is there for the neshoma to enjoy in addition to what is there for the guf to use.  The ability to see and appreciate that is the starting point for bracha (see Bad Kodesh by R’ Povarsky who elaborates on this Seforno further).

2) Yitzchak tells Eisav, “Sa na keilecha teliycha v’kashtecha v’tzuda li… v’aseh li matamim…”  He doesn’t just say, “Prepare a nice steak for me,” but rather he walks Eisav through every step of the process – gathering his tools, his bow, going out to hunt, preparing the food, etc.  I was once asked on an interview how to make a peanut butter and jelly sandwich.  I replied that you put the peanut butter on the bread, etc.  The interviewer then asked whether my hands would get all dirty doing that – I never said anything about using a knife.  The point he was creatively trying to make is that when communicating, it's best not to make assumptions.  If you are a trying to explain something technical to a non-technical person (I work in IT), best to be explicit and take nothing for granted.  I think in this case it’s fair to assume Eisav could figure out what to do without being told every detail.  Why did Yitzchak waste so many words? 
 
Netziv answers (see Seforno as well) that Yitzchak wanted to maximize Eisav’s reward for kibud av.  Yitzchak was about to give (or so he thought) Eisav a bracha and brachos have to be earned.  Had Yitzchak just said to bring him a meal, Eisav could have gone to the fridge and with little effort pulled out a steak and prepared it.  All Eisav would have gotten credit in that case is the end result.  By telling Eisav to go out and hunt game and prepare it, Eisav got credit for the whole process along the way – everything he did, from the hunting through the cooking, was a kiyum mitzvah of kibud av and earned reward. 
Tosfos (Yevamos 6a) interprets the gemara’s statement that kibuv av is a “hecsher mitzvah” to mean that all that’s important is the outcome.  If a parent says “Get me a glass of water,” filling the pitcher and pouring a cup is not the mitzvah – that’s just preparation for the mitzvah.  What matters for the mitzvah is simply that the parent’s needs are met.  The Netziv I think follows this view (Rashi in Yevamos learns the gemara differently and may disagree with this assumption) and is arguing that where the parent makes clear that he/she is concerned with the steps in the process, with how things are done, and not just the outcome, then the process becomes a true mitzvah and not just a hechsher.

From the fact that Yitzchak had to offer Eisav this chance to earn the bracha, Seforno sees evidence that Yitzchak knew that Eisav was not really worthy.  If not for this opportunity for the zechus of kibud av, the bracha would not work.  If that’s the case, I think it’s pretty amazing that this one act of kibuv av was all Eisav needed.  No matter how hard or involved the chore might have been, it's still just one mitzvah!  The Rambam in his Peirsh haMishnayos famously writes that in fact if a person does even one mitzvah lishma, he/she earns olam ha’ba.  “Ratzah Hashem l’zakos es Yisrael l’fikach hirbah lahem Torah u’mitzvos” – Hashem have us 613 mitzvos because each one is like a lottery ticket; you just need one ticket to win, so the more tickets you have, the better your odds.  Maharal at the end of Avos rejects this chiddush completely.  If someone is generally a bad person, argues Maharal, it doesn’t make sense that he/she should get olam ha’ba just for doing one thing right.  Maharal amazingly goes so far as to suggest that the Rambam wrote this for public consumption in order to inspire people to try to do mitzvos properly, but didn’t actually believe it -- this despite the Rambam calling it “m’ikarei emumah ba’Torah!”  Modern academics debate whether the Rambam concealed his true beliefs behind what he revealed in his writings; Maharal beat them by a few hundred years.