Could use some hangers to tidy things up and make the lines secure. To answer the question fuel being sucked into the engine prior to the pump may have problems if the line gets an air bubble in it and that gets sucked into the pump. also makes bleeding the lines more difficult. As a general rule you want the line to descend from the tank to the filter and then descend to the pump to make changing the filter easier and prevent air bubbles from entering the pump and causing air lock. If you have to have a high spot make it the filter so all the bubbles end up there and not in the lines.