some of the daily blessings such as thanking God for not making me a non-Jew or (in my case) a woman seem to be things which one would only make a blessing for once in a lifetime. Why are they made daily instead?
In general the morning blessings are a form of Birchas Hanehnin, which we would say every time we benefit, not once in a lifetime.
Shulchan Aruch HaRav writes:
ברכות השחר תקנום חכמים על סדר העולם והנהגתו מה שהבריות נהנין בכל יום שיברכו להקדוש ברוך הוא על זה בפעם ראשונה שנהנין הנאה זו בכל יום ויום להשלים מנין המאה ברכותה שחייב כל אדם לברך בכל יום ויום
The morning blessings were extablished by the Sages according to the order of the world and its patterns, that which creations enjoy every day, that they should bless G-d on this the first time they benifit from this benifit every single day, in order to complete the number of 100 blessings that a person is required to say every single day.
(See here for why it isn't necessarily required to actually experience the matter that we are saying a blessing on, like hearing a rooster.)
Regarding those blessings specifically - besides the general fact that the requirement is to say it every day anew even though the experience didn't stop other than by sleeping - he writes:
ולפי דברי המקובלים שברכות אלו הן על יציאת נשמתו בלילה שלא נדבק בה נשמת גוי או עבד או אשה גם הגר יכול לברך כן
And according to the words of the Kabbalists that these blessings are on the departure of his soul at night, that the soul of a Goy, Eved or Isha did not connect to him, also a convert is able to bless this way (שלא עשני גוי).
(The Magen Avraham is the source of this as halacha).
So there is an aspect to these blessings which are not about how a person was initially born. Besides this, since these blessings are about Mitzvos that a person is obligated in and בכל יום יהיו בעיניך כחדשים, a person should feel that the Mitzvos are something received new every single day.
I heard from Rav Gudlevsky (http://azamra.co.il), that every day and even every moment Creation is made anew.
So person should be happy every moment, that he/she still has all the blessings. Even such seemingly constant things as being a jew or being male or female can be taken away, G-d forbid.
There are plenty examples, that people not sure about who they are.
the point is to get in the habit of being thankful. a one time event won't change a person so much as the Rambam writes regarding charity
“If a person gives 1,000 coins at one time and to one person, this is inferior to the one who gives 1,000 times with 1,000 coins … for the latter case multiplies the spirit of generosity 1,000 times over, while giving just once will arouse awaken the spirit of generosity once, and then it ends.” – Commentary to Mishna Avot 3:15