Coin #1: Yep, Tunisian. The Arabic text around the tree translates to "Central Bank of Tunisia". On the reverse below the "5" is the denomination written out in full: "five millimat".
Coin #2: I don't have a Thai translation guide, but most of the legend around the
King Bhumiphol's portrait will be his name and titles. On the reverse, the first line of script appears to be the country's name, "Kingdom of Thailand". The second line consists of six symbols: the first two are the abbreviation for the phrase "Buddhist Era", the next four are the Thai numerals for the coin's date of issue. In your case, the year is "2542", or 1999 AD. Below this is the denomination; the swirly thing is the Thai numeral "1", the "1" is a Western "1" and the remaining characters are the denomination, "baht".
Coin #3: the bottom pic is upside down. When you turn it around, the country's name is at the top, the year "B.E. 2500" is at the bottom, and the denomination is to either side of the coat of arms: "5 satang". Year 2500, as you might imagine, was an auspicious year in Buddhist places, and Thai coins with that date continued to be issued well after the year ended. Year 2500 was 1957 AD, but these coins continued to be issued up until 1987 - thirty years later! Krause estimates the mintage as 46 million, KM/Y# 78, made of aluminum-bronze, CV 25¢ in Unc.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis