ZenCart problems with 2 shops

We have two old zencart shops to supervise and in each of them it gives a big problem with page alias. it should be something to do with the cache, when i clear it, the pages work. after time the error comes again. also in one of the shops there an error with the basket. for the beginning i need a programmer which can repair the http://baldo-shop.de. if you go on this shop in the menu to Kinder -> swalk, the message "Error: redirection" error comes. also theres is a problem with https. when i set a redirect on htaccess to https, in the articles i can`t click on the "add to basket", there comes also an error that the connection is unsecure. Normally I would suggest to the owners to create a new shop, but they stop working at the end of the year and therefore only repair with a not very high budget is possible. the version of zencart is the newest at the moment. if you have experiance in that and can make me a good offer for time you need and your hourly wage, i will order you. we need also good programmers for future, because we have a lot of projects...