To illustrate the difference between dialect and language allow me to give you these examples:
English is the language but British English, American English, Australian English, Filipino English, etc. are dialects.
Spanish is the language but Mexican Spanish, Chavacano (Philippine Spanish), Argentinian Spanish, Columbian Spanish, etc. are the dialects.
Visayan is the language but Cebuano, Hiligaynon, Ilonggo, etc. are the dialects.
Tagalog is the language but Cavite Tagalog, Batangas Tagalog, Bulacan Tagalog, Quezon Tagalog are the dialects.
As for standardization as the basis for determining which is a language or merely a dialect is potentially controversial thus I would not venture that way if I were you. This could give rise to notions of superiority and inferiority among peoples and set rifts instead of promote healing among them.
As for foreign influences, contacts through the trade routes, wars, political links, etc. have paved the way for countless cultural encounters that give rise to shared experiences resulting in language influences.
That is why many European languages have Greek, Latin, German, French or even Slavic influences. Even the Chinese and Japanese languages were not spared from Indian and more recently Western influences.
More importantly languages evolve. You would be surprised at the many Tagalog terms that are no longer used today but were commonly used in the past, to say the least.