Not a problem! Use a form that works well for you. If you want to see a guy that really tucks raw, check this out...
http://www.youtube.com/watch?v=sl9Uj...1&feature=plcp There are lots of guys that don't tuck this much, but just be careful about really flaring your elbows out too far. It almost becomes a BB type bench then, and it can be harder on the shoulders.
It can be hard to find good spotters. Sometimes they just like to grab the bar. I am ok with that (someone shadowing the bar), if I am using my usual spotters. They won't pull anything unless I need it, and they are honest with me when they do it. Grinding reps a lot can be hard on you. If I have a hard set where my spotter keeps it going by taking 5-10lbs off the bar, that is ok with me. It is better than rally grinding it out and burning out in the weeks to come. Again, this is just my opinion, but a lot of people train like this. I'm not advocating this for every set, but if you go for an overload with boards, there is nothing wrong with it.
I think 225 for reps is good. How long have you been training, and what did you start with on the bench. If you want to compete, try to work in paused reps every once and a while. I do all my low rep board work for a really short pause. It is hard to get a good TNG off the boards, so I just pause them. Working on a pause for regular reps helps too. It isn't something you have to do all the time, but just work it in every once and a while.
I hope this helps!