hi hopefulhomebuyer,
It looks like you're putting your Suze Orman FICO Kit to good use and congratulations on paying off those 3 nearly max'd out credit card accounts. In response to some of your questions:
1. Don't close the accounts you just paid off. Place the cards sealed in an envelope if you must, but leave them open so that you still have this credit available to you. This will reflect positively on your FICO score since the more revolving credit available to you, the better your score.
2. There's no way to estimate the change to your score upon removing 2 collections, but the more recent the assign dates on these collections, the more of a negative impact they're having on your score now and thus the more positive impact to your score upon removal.
3. You mentioned the 3 credit cards paid in full had recently been late. These recent late payments, in addition to the collections, are probably also having a negative effect on your score and could even be hurting your score more than the collections. Don't worry, though, since now that your balances are much lower and your payments are up to date, your score will continue to increase as you continue to pay on time and keep your credit card balances low.
Good luck.
Barry