"The man is cool!"
Those are all correct. I will say though if you want to find a subtle nuance, 빵은 맛없습니다 for example CAN BE translated as "bread is bad" as in you think all bread tastes bad. It doesn't have to mean that every time though; it can also mean "the bread right here isn't good." That's the problem with no context. Thus 음식이 맛있습니다 can be translated as "the food (here) is good". It probably will never mean, on the other hand, "I think all food is good (in general)".
The difference between using 는 (은) and 가 (이) is sometimes hard for beginners to understand. The phrase won't have it's meaning changed if you use one or another, the only small difference between these two is that when using 는 (은) you are comparing the main subject to something else. Example: (The cat는 is under the bed, and the dog는 is besides the bed.) As you can see I compared two subjects to something (the bed). When you use 가 (이), it doesn't have to be compared to something else. Example: (The cat가 is under the bed). You didn't compared the cat to something else. But you don't really need to always remember how to use them when speaking, because the difference between these two is really small, so a native speaker will understand you easily.
In my experience, yes. The 'ㅅ' is pronounced as 'sh' when put in front of the 이, 여, 야, 요, and 유 vowels. The same goes for 'ㅆ'. In the example that you used, since the next sound following the 'ㅅ' is an '이', then the pronunciation becomes a 'sh' sound. Additionally, if it is placed at the end of a syllable/grouping, then it-- usually-- makes the 't'/soft 't' silence sound. Though this is dependent on what characters are used in the following character/syllable, and in this specific example you used, this is not the case. For example, someone correct me if I am wrong, '것' is roughly pronounced as 'geot', while '것은' is pronounced as 'geo-seun'.
Essentially, when the 'ㅅ' is placed at the end of the character/syllable, then it only makes the 's' sound when immediately followed by a vowel in the next one (e.g. 멋있어). In any other case, it's probably safe to say that the pronunciation is closer to a soft 't' sound (e.g. 다섯)
A lot of this type of thing is just immersing yourself in the language and learning exceptions and spelling/pronunciation rules via experience. I hope all of this made sense and good luck in your learning endeavors.
Actually, the /ㅁ/ in Korean isn’t exactly the letter “m.” I remember a native speaker saying once that the sound of ㅁ is actually in between the sound of “m” and “b,” somewhere not too soft nor too hard when pronounced, if you get what I mean. They only indicated that it is the corresponding character to “m” since it is what it mainly sounds like and so you won’t confuse /ㅂ/ with it when pronouncing words.
Is right if say 남자가 멋있다 (the man is cool) instead? because the 있습니다 is more like 'to have' so the sentence in this one says 'the man has coolness', so... Someone knows? If is right to use the '있다' instead of the '있읍니다', i mean, i feel like is more accurate the '있다' in this one ✌