1) R' Zilberstein tells the following story: There was a Jew who lived close to the home of the parents of the king of Morocco who wanted to say the bracha on seeing the king. The king would visit his parents occasionally, coming late at night in private when he could go without his whole entourage, and so this fellow asked his neighbors, the king's parents, if he could step in for just a moment when the king was there just to say the blessing.
One night he gets a knock on his door at 2:00 AM and is told the king is there and to come. He gets up, wakes his 12 year old son, and they go. They bow to the king, and the man and his son say the bracha. As they are about to leave, the king asks the man why he woke up his son and brought him along. The man answered that his son will be bar mitzvah soon, and so he wants to train him to fulfill the mitzvah of honoring the king with this bracha. When the king heard that, he took out his checkbook and wrote out a check for a $50,000 bar mitzvah present. The man was a bit taken aback and said to the king that it was totally unnecessary, and if he wanted to give a gift, a check of a few dollars would suffice. The king responded that although the man said the bracha on malchus, he obviously doesn't understand what malchus means. A king doesn't write a check for $10 like an ordinary person. $50,000 is the minimum gift for a king. Malchus operates on a different scale.
Said R' Zilberstein: We are standing on the threshold of chodesh Elul. We are getting ready to approach the King of all Kings. If a melech basar v'dam won't write a check for a petty amount when he wants to give, kal v'chomer that the Melech of all Melachim who wants so much to be able to give us mi'tuvo v'chasdo will not write us a check for a petty amount.
Don't daven for petty things. The King is ready to give. We just have to ask and to be ready to receive.
2) We have in our parsha the mitzvah of tzedaka and the mitzvah of aliya la'regel. The gemara (Pesachim 8) tells us הָאוֹמֵר סֶלַע זוֹ לִצְדָקָה בִּשְׁבִיל שֶׁיִּחְיֶה בְּנִי אוֹ שֶׁאֶהְיֶה בֶּן הָעוֹלָם הַבָּא. Rashi explains: בדבר זה ולא אמרינן שלא לשמה עושה אלא קיים מצות בוראו שצוהו לעשות צדקה ומתכוין אף להנאת עצמו שיזכה בה לעולם הבא או שיחיו בניו. The extra kavanah that tzedaka should serve as a merit so that one's son should live or that one should get olam ha'ba does not diminish from the main kavanah l'shem mitzvah.
Tosfos is bothered by why this does not amount to serving Hashem al menas l'kabel pras. Tos answers that when a person pledges with an al menas... condition, they do so knowing that their request may not be fulfilled, and in their mind and heart they are prepared to give anyway. I saw one of the Moroccon chachamim, R' Yaakov ben Shabbat, quoted a different answer. He suggested that the tnai of al menas is problematic only if the basic mitzvah of tzedaka is being done on a conditional basis. However, if one is giving above and beyond what is required, there is no issue.
He reads these answers into the pasuk נָתוֹן תִּתֵּן לוֹ וְלֹא יֵרַע לְבָבְךָ בְּתִתְּךָ לוֹ כִּי בִּגְלַל הַדָּבָר הַזֶּה יְבָרֶכְךָ ה׳ אֱלֹקיךָ בְּכׇל מַעֲשֶׂךָ וּבְכֹל מִשְׁלַח יָדֶךָ (15:10) The first part of the pasuk נָתוֹן תִּתֵּן means we are not just talking about someone who gives the minimum to fulfill the mitzvah, נָתוֹן, but someone giving more than required, hence the double language, נָתוֹן תִּתֵּן. Secondly, the pasuk is telling us that when you give, even if you don't get what you want, don't show regrets - לֹא יֵרַע לְבָבְךָ בְּתִתְּךָ לוֹ. If you meet those conditions, then your giving can be כִּי בִּגְלַל הַדָּבָר הַזֶּה יְבָרֶכְךָ ה׳ אֱלֹקיךָ בְּכׇל מַעֲשֶׂךָ, for the sake of receiving the bracha that you want and need. Otherwise, beware of conditions.
On the very next amud the gemara writes with respect to aliya la'regel אָמַר רַבִּי אָבִין בַּר רַב אַדָּא אָמַר רַבִּי יִצְחָק מִפְּנֵי מָה אֵין פֵּירוֹת גִּינּוֹסַר בִּירוּשָׁלַיִם כְּדֵי שֶׁלֹּא יְהוּ עוֹלֵי רְגָלִים אוֹמְרִים אִלְמָלֵא לֹא עָלִינוּ אֶלָּא לֶאֱכוֹל פֵּירוֹת גִּינּוֹסַר בִּירוּשָׁלַיִם דַּיֵּינוּ נִמְצֵאת עֲלִיָּיה שֶׁלֹּא לִשְׁמָהּ. Hashem deliberately did not make the fruits of Yerushalayim extra delicious because otherwise people would make aliya la'regel just to eat the fruits and not for the sake of the mitzvah. So what? If the shelo lishma of בִּשְׁבִיל שֶׁיִּחְיֶה בְּנִי אוֹ שֶׁאֶהְיֶה בֶּן הָעוֹלָם הַבָּא does not detract from the mitzvah of tzedaka, why should making aliya la'regel for the sake of enjoying the fruit detract from the mitzvah?
R' Shteinman answered that the bracha that comes from the mitzvah of tzedaka is part of the outcome that Hashem guarantees from the mitzvah. Therefore, having that in mind does not detract from the lishma. However, eating fruit is not part of what the Torah says the outcome of aliya la'regel should be. It is merely a side benefit of the trip. In that case, having that side benefit in mind diminishes from the mitzvah itself.
Shem miShmuel in the introduction to Eglei Tal discusses whether the enjoyment one gets from learning detracts from the lishma of the mitzvah. His answers is very similar to R' Shteinman's sevara. Enjoying one's learning is part and parcel of the process of study. It is an inherent benefit and outcome of doing the mitzvah, not a side point. Therefore, it does not diminish the lishma of learning.