To pronounce two a's would be better. Some people just make it a long a.
Actually these Arabic words have more complicated pronounciations as they have at least two different sounds for "a" in Arabic.
In fact this is the case with saat as well. The first a sounds different than the second.
But it is possible and easier to make it one syllable as "saat" with a long 'a'. I would suggest this second way.

There arent many. Just a few. In fact right now I cant think of others. Saat is the most common.

By the way, all the suffixes follow the rules.

You are right. It breaks the rule. The word isnt originally Turkish.

You know vowel harmony. Now look at these words: "insan, patates, domates" they have both sharp and deep vowels. We just have to live with the irregular words. So when applying a suffix the last vowel only counts.

Your guees is correct. it is sa-at.

There are some other irregular words: "bravo", "tren", and a few more.
Though we have cvcc we dont have ccv or ccvc syllables. So these are irregular as well.

Good question.
It applies to suffixes.
Example:

Dative Case Suffix: -e -a (meaning to, towards)

If the last vowel is a deep vowel (a,ı,o,u) we use -a
okul+a :to the school

If the last vowel is a sharp vowel (e,i,ö,ü) we use -e
deniz+e :to the sea

But if the last vowel is a deep vowel (a,ı,o,u) and the word ends with the vowel we put the bufer y inbetween:

su+ya: to the water
hava+ya: to the sky
Ankara'ya: to Ankara

But if the last vowel is a sharp vowel (e,i,ö,ü) and the word ends with the vowel we put the bufer y inbetween:
kedi+ye: to the cat
Türkiye'ye : to Turkia

http://www.turkishlanguage.co.uk/nouns.htm

I hope others do realise the trick with "o-kul" but "o-ku-la" and "ben" but "be-ni". OK, lets continue,

exercise 10:
Telefon çalıyor. Lütfen telefona bakın.

exercise 11:
Ben televizyon izliyorum.

exercise 12:
Televizyona bakmaktan gözlerim ağrıdı.

bod,
perfect. You are a syllabling master.

Congratulations Nightingale,
you are a syllabling master.

Others can try the exercises on first message.

Nightingale,
you got 6 and 7 right, 4 is still available to anyone. You have now two bonuses. I added one more rules to the list on the top to make it clear.

Mella,
you got them all right except number 4 and 6.
It is >oy< na ma ya in 6. Again check new rule 3 on top for details.
Unfortunately no bonuses this time as you need to be first to make them but well done anyway.

Anyone can try these:

exercise 4:
Ben Türkiye'ye gitmek istiyorum.

exercise 7:
Ben seni ararım. Sen beni arama.

exercise 8:
Sen nerede yaşıyorsun? İstanbul'da mı?