Hi Knowledge and welcome to the Project Meditation community,
No, you're not cheating, you're using a meditation technique and experiencing a form of meditation by doing so. You're not doing anything wrong.
Like you say, there are many different techniques out there, but I would categorise these into 2 main areas... "focused" and "unfocused".
"Focused" itself can be split into 2 subcategories, "objective" and "contemplative".
Focused - Objective is the type of meditation where you put your focus onto a single object i.e. focusing on the breath and attempting to keep it there.
Focused - Contemplative is the type of meditation where you start with a thought or image etc. and then allow it to flow and just keep your focus on what is happening. This is the sort of meditation you are describing above.
Unfocused is the type of meditation taught by the Transcendental Meditation organisation, which is also taught under different names and also happens to be the same meditation technique Michael offers for free with his "Discover Meditation" downloads from this very site. It is commonly known as "mantra based meditation" and involves using a mantra (word/sound) that repeats itself over and over. The trick with this type of meditation is to initially bring the focus to the mantra, but then to just let it repeat itself as it wants to, loudly, quietly, fast, slow etc. whilst just observing it and not trying to force it into any particular pattern using focus (hence why it is un-focused

).
Almost all meditation techniques you've come across should fit into one of those three categories above.
How you sit doesn't really matter, as long as your body is going to be comfortable for the duration of the meditation practice, and as long as you're not likely to fall asleep (i.e. lying down or having the head supported in a comfy armchair is conducive to making the body relax into sleep). A lot of people find sitting cross legged or in the lotus position uncomfortable and so, sitting on a reasonably comfy chair is a good alternative, and there are also meditation stools which allow a sort of kneeling position whilst preventing the weight from sitting on the actual lower legs. Each person will find what's best for them.
What is experienced during the meditation is not really of concern. It is said that if you use a focused meditation practice then you are using your mind and keeping your focus in your mind, thus preventing yourself from going into deeper states of meditation. Using the unfocused (mantra) meditation technique allows for deeper states as you let go of that thing that's keeping you in your mind. Of course, whichever method is practiced there can be images, thoughts and suchlike arise. Simply choose to recognise that this will happen, accept them for the thoughts they are and let them go.
Emotions arising can be common and will vary from person to person. Almost everybody will have some issues or emotional things they've held back during 'normal' life, and it's the mind that suppresses or represses these things. By practicing meditation you start to let that self-mind control go and the emotions can come to the surface. Again, recognise this will happen, and allow the emotions to come up and be released. Whatever they are, they are from the past and do not relate to the present moment, so really serve no purpose now and will only cause issues if you hold onto them.
The main benefits of meditation is how it effects your life when you're not practicing meditation. The release of emotions, the relaxed state of mind, the clarity of seeing, the awareness of being in the present moment etc. these are all things that show up over time in your real life after you've been practicing. A lot of people believe that the benefits are within the meditation practice itself and get frustrated seeking for them there and come out of meditation saying things like "it was interesting and relaxing, but it's not really done anything". There is no magic bullet of enlightenment to be found within meditation. Enlightenment is found within You as a whole, as part of the whole universe and your life within it. Meditation is a tool to help us recognise and become aware for this purpose.
Hugs
Giles