Would my chances of getting a weird as timetable be high? (Big gap between each class, early morning lecture and etc) and if I do get an awful timetable, would I be able to make the timetable a bit more decent when the timetable's released on the 26th?
Not really, it's not like they purposely punish you for being late.
You can easily swap into the classes with under 100% capacity fulled. Sometimes, these might be the less desirable classes (early or whatever), sometimes not. Keep in mind people are probably taking IT subjects from all different degrees with all different configurations of subjects, so, its not like everyone will be going for a single time leaving only the objectively horrible ones behind. Everyone has a different set to fit it into.
Also, you can get the spots people swap *out of* when allocate reopens. I'd suggest during this period you check allocate a few times
a day to try get into any spots people swap out of (if you think those spots are better anyway).