TLDR: Good idea to ask, but you probably don't need to worry. 1) Decent odds those have been there since the day the tank was built. If it were my tank I'd fill it up, keep an eye on it, and months later when they haven't changed never worry about it again.2) If they do change (and I don't mean between draining and filling the tank, I mean over time), then there may be cause for concern, but it sounds like that isn't the case.3) The cost to reseal the tank properly (disassemble the panels, remove all traces of silicone, reassemble) won't be as bad as a plastic trimmed tank, but may well exceed whatever you paid for this one.4) Simply cutting the silicone off the inside (or not) and smearing extra at the seams will not only make the tank look worse, but it will add nothing to the structure of the tank.5) Something you can do is make sure the stand is smooth/flat as an uneven support is the cause of most tank failures.
