Answer to the first question has been given by ナルトさん. But any new answers or thoughts or suggestions are really appreciated!!
Answer to the second question can be extended, as only a touchstone was laid down by ナルトさん, and this is a limitless answer, so anyone is free to give their opinion.
I have tried to give answer to question #3 based on ナルトさん's reasoning but I am not sure about it. So, this question requires more in-depth answers.
Using ている has been tricky for me. I have always stumbled upon, as when to use ている form and when to use た/だ form (Past) in cases of Punctual Verbs. So, in order to get a better understanding I revisited my English grammar book, to see the difference between Simple Past and Present Perfect. Over there I found a few rules that were to be followed, to distinguish, between Present Perfect and Past. Following are the rules that were laid down:
English Grammar Principles for usage of Present Perfect and Simple Past
(Please note I would be using only those verbs that are Punctual Verbs in Japanese)
Where time is used or the focus is on the time, use Simple Past E.g. I turned on the light at 8. Whereas, if time (whether known or not, is immaterial) is not used then we use Present Perfect. E.g. I have turned on the light. As Simple past (In English) focuses on the point of time a thing/act happened.
When you tell about life experience and travelling experiences, use Present Perfect. E.g. I have graduated and I have been to NY 3 Times.(This part has already been answered by @The Japan Nomad Girl)
Time when in essence has not been completed, like this week, this year etc. (however usage of last week or likewise vocabulary would make time in essence complete and would make the sentence Simple Past). E.g. I have worn new shirts this week.
When the Action has been performed in the Past, but the focus is in present, then we use Present Perfect E.g. I have lost my bag (Focus on Present). Whereas, when focus is in the past, use Past. E.g. I lost my bag (Focus on Past).
When we talk about travelling/residing action. In case, if we imply that I am still there or still in the place of travel then we use Present Perfect. Whereas, we use Simple past, though it would state that I went/resided/etc. It won't mean that I am still there. This is same in Japanese as well, like 行っている and 住んでいる. This last point does not need an answer.
Q1. Do the Punctual Japanese Verb (Please note I am only concerned with Punctual Japanese Verbs) also apply the above English Grammar principles for differentiating the use between ている (present perfect) and た/だ(Past). That is to say, whether the Punctual Japanese Verb are used identically in the above referred cases.
E.gs. Point 1: Will 私は明かりをつけている (Present Perfect) be used as time has not been mentioned and 私は8時に明かりをつけた (Past) be used as time has been mentioned
Point 3: Will 私は今週新しいシャツを3枚着ている (present perfect) be used as the week has not ended, and 私は今週新しいシャツを3枚着た (Past) be used as week ended.
Point 4: Will 私はバッグを紛失している (Present perfect) be used when we Focus in the present. Whereas, 私はバッグを紛失している (Past) be used when the focus is in Past.
Q2. Are there any other ways to differentiate between the ている (present perfect) form and た (past) form when we talk about Japanese Punctual Verbs?
Q3. Could anyone highlight the difference (also the difference in nuance) between ている (present perfect) form and た (past form) in cases of Punctual Verb!? (I have been literally struggling to differentiate between Punctual Verbs ている form (Present Perfect) and た (Past) for over 1 month and my Japanese Language learning has come to a halt for past 1 month, as I am not able to differentiate between the both)
There are other posts but the difference highlighted is mostly pertaining to Durative Verbs and Not Punctual Verbs, and where the concept of Punctual Verb is highlighted, it is not dealt thoroughly and it creates lot of confusion. So, an answer to this question might give clarity upon the individual concept of Punctual Verbs' ている and た forms, and would also highlight the difference in Present Perfect form in Japanese and Present Perfect Form in English. Following are some links which though has dealt this issue but has focused more on Durative Verbs than Punctual Verbs: