Mishka (Мишка) and Myshka (Мышка) are pronounced differently . You won’t confuse the two. I know many Slavic languages don’t have the ‘ы’ sound and people struggle to pronounce it. Russian, Belarusian, Polish langauges have this sound . Ukrainian ‘и’ is pronounced midway between Russian ‘ы’ and ‘и’.
My favourite modern feminine name could ‘Vesna’. Belarusians don’t have this name.