1: Usually the hour glass is around the second main item Morg rushes, but depends on how quick you think you are going to be team fighting, In team fights you want to be in the middle of their team creating chaos with your ult. either the whole team will get stunned and eat fairly decent amount of damage, or it will cause them to split up, in which case, your team then goes after the squisher target such as that AD carry or that AP assassin and removes them from the team fight equation. Your survivability only increase with the hourglass so as soon as you flash ult, they dont just burst you down before it can go off.
2. Roaming on her is fine, but usually you are worried more about mid. If you know your opponent went back, and your ult is up and you see that the enemies are overextending, coming in behind with your ult sets up easy coordinated ganks with your team. Make sure you ping and they know your coming, Also make sure they have enough health for it to work. Last thing you want to do is go try to help gank and they don't have enough life to come in and help you. Common sense and basic analytic skills go along way. Also you don't want to deviate away from your farm to much, unless your situation really calls for it, Protect your team, but try for ganks that have a very high success rate, to help facilitate that farm you are leaving behind. If your ganks fail then you have just missed farm that could of helped you get both a gold and level advantage over the opposing mid, basically losing a great chance to snowball.
3: Morgana almost always ganks the same way she goes in for kills versus the mid. You initiate with your ult. Ideally once it goes off, you pool right underneath them as soon as it does. The reduces their magic resistance more for her Q to eat face, allows for greater time for your pool to chip away at their life. After you landed your Q its usually time to ignite. That does the vast majority of chars in. It is possible to gank earlier but not really recommended, but very skill shot reliant on landing your Q. At level six with your ult your chances increase exponentially.
4: Stealing a blue with Morg either takes some coordination with a teammate or requires you having pretty decent vision on the enemy blue and timing a perfect Q, easier done if the enemy's blue is warded particularly in their bush right next to blue because that is where the smart players will kill they blue.
5: Smart cast is fine with more and IMO definitely the preferred way to go. And as for her shackles, as long as the enemy team is in initial range and remains so they ALL can be shackled.
6: As for farming with her w right away, its probably not that smart to spam it early on as it will eat alot of your mana with little net benefit. Focus more on last hitting and minor harass, minding how much mana you have. If you enemy is smart and playing back behind their minions so you can never harass with Q, Then wait til they walk foreward at their caster minions and pool underneath their feet. That way the spell then does double duty in harass and CS. Its better to just worry about last hitting early on to keep that creep score up, and then once your w hits level 3 then each wave, put it under the caster minions and clear half the wave, quick easy and from a safe distance. Depending on who you are laning against how aggressive/defensive they are in lane its not a horrible idea to try and land a few auto attacks. Your passive many times will replenish that life you lost in the exchange in short order. Just be smart about doing it, watch for gank set ups, and don't over extend doing so.
6. As for skilling order, sometimes you want to consider taking your shield a little earlier when laning against AP with good harass and CC. Many times one point in the ability can/will save you from ganks and stuns. Using your judgement goes a long way with that decision. Are they landing alot of ap harrass/ cc on you? Then its definately should be on your mind. Against many it is what makes morg and very hard target to gank.
7. As far as hard counters, Kassadin is definitely one. You go in to start the kill with your ult he just ults away gaining distance and breaking yours and his is back up in four seconds. A smart player going against a Morg knows its all about surviving her combo burst, because if they can dodge, move out of range of some of the damage all of a sudden Morg is vulnerable and in trouble. Prime example would be a good fizz dodging by hoping up on his trident.
Hope this helps, I am in no way any kind of expert, but alot of this is accepted morg knowledge. Good hunting!