Hello,
1) If you use Chrome use inspector tools (other browsers also have similar tool) https://developers.google.com/web/tools/chrome-devtools/inspect-styles/?utm_source=dcc&utm_medium=redirect&utm_campaign=2016q3 inspect elements that you want to change https://gyazo.com/32a313bb6dbb8887b9c2d0f04a2958c6 and just edit CSS styles according to your needs. For example
.information-blocks .accordeon {margin-bottom: 0;}
2) a) to move the arrow
@media (min-width: 1200px){
.navigation .submenu .accordeon-title:after {
right: 10px;
}
}
b) both items have the same line-height http://prntscr.com/jbvuo9 and http://prntscr.com/jbvuyu So, don’t understand what exactly you want to change.
Regards