Change Login Code

Hi, This is a three part job. Part 1: We need to change our login box at the top of the home page and on our [login to view URL] page so that it will login directly to the customers My Account page unless they try and login after clicking checkout. Then it would be forwarded to the [login to view URL] page. The site is oscommerce based but does have some modifications. It still should be a very easy fix and will send files as requested but will not give access to site through FTP. Part 2: We have also noticed some login problems. Customers have complained that they cannot login. We have tested this and have found a problem that happens but its very random. I enter our password and it wont login no matter how much I try. If I clear the cache and cookies it works again. I think its when a customer clicks on the login link from the signup form. We tested this using the latest Firefox browser but it must be happening in all browsers. PART 3: Customers complain about the Can't Remember Password function not sending them their new passwords. We test it and it works fine but we would like to see if anyone else can see if there is a problem. It could be their spam filters but when we tell them to check their spam folder they tell us there is nothing in there. We would like to get these problems worked out. Its probably just a simple code error on one of the pages. We would like for these changes to be made ASAP as customers are complaining a lot. Thanks, Jamie