Is my English strange?

①wow! This apple is pretty delicious! Where does an apple come from?
このリンゴとても美味しい。どこの産地のリンゴ？

②How often do you travel abroad on business once a year?
一年間でどれくらいの頻度で海外出張に行くの？

③How much does it cost to join?
参加料金はいくら？

④I like to watch and play baseball while I drink beer.
ビールを飲みながら野球を観るのが好き。

Is my English strange?

①Wow! This apple is pretty delicious! Where did an the apple / it come from? ("Where was it grown?" <--- though this is not so common of a question.)
このリンゴとても美味しい。どこの産地のリンゴ？

②How often do you travel abroad on business one in a year? (We often use "a/an" when referring to 'one' of something in English. For example, 'in an hour'; 'for a month'; 'in a day's time...')
一年間でどれくらいの頻度で海外出張に行くの？

③How much does it cost to join?
参加料金はいくら？

④I like to watch play baseball while drinking beer. ("I like to drink beer while watching baseball" would also be okay!) 
ビールを飲みながら野球を観るのが好き。