Salam brother Ibn Yahya,
What do you think tawwassul means? It is only logical that the only reason you do tawassul through the imam is that you want him to intercede for you. It is asking the imam directly to ask Allah. There is no other type of tawwassul.
Salaam alaykum wa rahmatullah,
Welcome! May your stay turn out fruitful to you and to us.
There are three types of tawassul:
1) Beseeching Allah (swt) using His Names and Attributes.
2) Asking Allah (swt) for something by mentioning a good deed you have done. For example, you gave a poor person money so when you pray, you say, "ya Allah, for the sake of the charitable act I performed today, please grant me such and such".
3) Asking a pious individual who is ALIVE to supplicate to Allah (swt) for you.
Having said that, since I am extremely spiritual as well, I do not mind going to shrines and supplicating to Allah (swt) for what I want or need. I will clarify that statement. If I go to a shrine - let's say I go to Karbala to visit Imam Hussain [ra] - I will offer 2 rakat
facing the qibla. Then, I will raise my hands and supplicate to Allah [swt]. I will not ask Imam Hussain [ra] for anything.
I believe - and this is my personal belief which may or may not have a root in Islam - that you can be closer to Allah [swt] standing next to a holy person or standing on holy ground. Therefore, I do not mind visiting shrines because I am in proximity to a saint. But that does not mean I will pray to the person buried there. My supplication is to Allah [swt], my worship is for Allah [swt] and my sajdah is to Allah [swt].