Yes you can definitely use past simple and present perfect but you shouldn't use the verb accomplish in that sentence.
I have also checked your first post and in my opinion there are few mistakes. Some of them are grammar mistakes while other sentences sound a little bit too Italian. English is a Bitch.
Have a look...
First of all please excuse my English for any possible mistake.
I am going to explain you the purpose of this topic. In my opinion the best way to learn a language is to speak it, therefore it could be a good idea to use this topic to discuss about A.C. Milan in English. We can discuss about: matches, players’ performances, Galliani’s Berlusconi’s and Allegri’s claims, and everything else regarding A.C. Milan.
Anyone can suggest a question and discuss about it, also by quoting and responding to other posts. In this way we will debate just as in any other thread in Italian.
What do you think about this idea? I hope that you will appreciate this project as in my opinion it could be a very useful learning tool!
In this topic please speak only in English!
Let me start off this subject. Are we going to grab the third place this year? Let’s discuss about it!
Great, " First of all" is a right form but "to begin with" too. I learnt it by the reading of " A Christmas Carol" by Charles Dickens. It begin with this expressioni : " Jacob Marley was dead: to begin with."
Yes, you're right: ing form is better than simple present which however isn't a mistake.
I prefer "is speaking it" because when the italian traslantion is " il + verbo" " il parlarlo" in this case, ing form is preferable.
Yes, it's another right form to express the concept.
Yes, you're right. I have to put "by".
You can omit "that", but if you put it, it isn't a mistake.