"Religious rituals after death"

For a long time, a question about "Religious rituals after death" is bothering me. It's a purely personal question related to me
If I put my views before some Priest (Purohit), he may reply to his advantage and may say a big 'NO' to what I think just because I am a Brahmin! I don't know what stand any spiritual leader will take. That is why I am putting across my personal views on to my blog to elicit your opinion /views in the matter. Let me make it clear first that I do believe in God as a supreme power but am not a blind follower of several religious rituals.

(1)- After attending umpteen number of religious function of some body's death i.e. 9^th day to 13^th day and thereafter Monthly & Yearly shradh rituals, I have started thinking in a different perspective.
No body knows where one goes after death i.e. to hell or heaven. In my opinion, we experience all the miseries of life i.e. hell or comforts of heaven in our life time before death. We should not expect to go there after death. May be these rituals are conducted to appease God to send the departed soul to Heaven or to make his/her soul rest in peace. It may happen that during his/her life time, we may not have bothered to look after them or always blaming or fighting with them but suddenly after their death we start performing pooja for resting their soul in peace! Fine, but why to make the function of pomp and show by calling all & sundry? Why to accept costly gifts from all of them on 13^th day?
People attend these functions for various reasons. Some are compelled because of family bondage even if they do not see eye to eye with the deceased or his family, some for the fear of back lash by God if not attending the function but as per my observation, majority of people come for chit chat, meeting each other and to enjoy the sumptuous food items prepared on the occasions .
What is the need for such show off and formalities? So many people have to waste their leave just to come and go back after eating! So many people have to come from far off places. All these are not for a day but for continuously for 4-5 days and even full 13 days. Is it not a colossal waste of other's time and money?
If at all we have to follow rituals of feeding people, why not to do away with the rituals followed from 9^th day to 13^th day/monthly/yearly just by visiting temple by family members and pray for the soul to rest in peace followed by arranging food for the needy like those staying in orphanages, old age homes, destitute homes & likes and get their blessings for doing something good for the needy. Nothing else to be done or performed.
Can family members be bound by my wish if made as a part of personal WILL?
(2)I understand that if somebody donates his/her entire body on death to Medical College for their studies/research than no rituals need to be observed. Is it true and if yes, why exemption under this category?
I am sure you would take some time out of your busy schedule to quench my thirst for answer to the above.