1- Yes riwayat about consumption of alcohol are absolutely right. Quran and Ahadith condemn the Ahadith but drinking of alcohol is different from the consumption of alcohol in medicine
Yes still there are the ruling if you can find an option where there is no alcohol nothing is better than that.
But if not then : It is permissible to use them to the extent required for treatment in case of necessity.percentage not mentioned .
At one place Aagha e Seestani may Allah grant him long life said
alcohol is tahir (ritually clean) but it is not permissible to drink it. Using perfume and medicines mixed with alcohol is permissible .
As per the ruling of Aagha :
They are pure; and since the alcohol used in them in medicine is so minute that it dissolves in them, it is therefore permissible to take them also.
Now issue of marriage and Education .
No doubt Education is very important
It is compulsory on both male and female as Rasul saw said
Aquire knowledge from cradle to graveyard.
Then when one can get married? That means marriage is not an obstacle to marriage I know there were many people male and female . In some case only one of them in few cases both husband and wife were student and they got married while they were studying and Alhumdulillah they were able to complete their education with success and they are good parents and they are giving their contributions to society by teaching in Islamic schools and weekend madersa.
I suggest you to get hugger Education but as you mentioned you are 25.do not delay in your marriage
I'm pleased to k know that not only planing to complete your medical studies but you want to study in hauza. That's great it is a nice plan. Discuss with your parents and follow their instructions