Tense correctness in sort of a personal statement

Hi. Let us pretend there is someone who is applying to a school of diplomacy, if there is one (I don't know), but as the name implies, I am sure it is a school that teaches about diplomacy and presumably for people who want to work in the area of diplomacy. Anyway, would you check if tenses are correct for these sentences that are presumed to appear in sort of a personal statement telling about him or herself, addressed (sent) to an admission officer or someone responsible for admission? I have highlighted (in bold letters) the verbs (as I presume they are) for your convenience.

1. I grew up in one of the biggest, culturally diverse metropolitan cities in the world and interacted with people from diverse backgrounds in an almost daily basis during those years.

2. As I was growing up, I traveled extensively to other countries, experiencing the various types of lifestyles and appreciating the values they offer.

3. I have even been to such little-known countries as XXX and YYY, which are the countries, I presume, a few have both a previlege and chance to visit in their life time. I learned a lot from my travel to those two countries.

4. Based on a small account of my past experiences and achievements, I hope you will give me a serious consideration.

One more thing: would it be better if I wrote the no. 4 sentence like this? Based on what I said, I hope you will give me a serious consideration. I have a qualm about using a present perfect in no. 3 when the no. 4 sentence said, "Based on a small account of my past experiences and achievements ..." I feel what precedes it should all be in past tenses (possibly preferably, if not "should be"). Any help from you teachers would be deeply appreciated.