Is a girl obligated to accept a suitor who is religiously committed and of good character from her own country, but holds European citizenship and resides in Sweden, considering that she has received numerous unsuitable marriage proposals?

If the suitor is pleasing in his religion and character, and his residence in Sweden is permissible according to Sharia, or he intends to stay in your country, then seek Allah's guidance (perform Istikhara) and accept him. This is based on the Prophet's (peace be upon him) saying: "If someone whose religion and character you are pleased with proposes to you, then marry him. If you do not do so, there will be tribulation on earth and widespread corruption." And if he is residing there for the purpose of inviting people to Allah (Da'wah) and desires a wife to assist him in that, then this is among the best of deeds.